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https://hackaday.com/2025/03/22/acoustic-levitation-gets-insects-ready-for-their-close-up/ | Acoustic Levitation Gets Insects Ready For Their Close-Up | Tom Nardi | [
"digital cameras hacks",
"FPGA"
] | [
"acoustic levitation",
"Photogrammetry",
"ultrasonic levitation"
] | The average Hackaday reader is likely at least familiar with acoustic levitation — a technique by which carefully arranged ultrasonic transducers can be used to suspend an object in the air indefinitely. It’s a neat trick, the sort of thing that drives them wild at science fairs, but as the technique only works on exceptionally small and light objects it would seem to have little practical use.
That is, unless, you happen to be interested in exceptionally small and light objects. A paper titled
Automated Photogrammetric Close-Range Imaging System for Small Invertebrates Using Acoustic Levitation
describes a fascinating device which allows the researchers to image insects in what’s essentially a weightless environment.
With the delicate specimens suspended in front of the lens, there’s no background to worry about and they can be perfectly lit from all angles. What’s more, with careful control of the ultrasonic transducers, it’s possible to control the rotation of the target — allowing researchers to
produce 3D scans of the insects using just one camera
.
There isn’t a whole lot of technical detail on the device itself, other than the fact that spherical chamber has a radius of 60 mm and is fitted with 96 Murata MA40S4R/S transducers operating at 40 kHz. The paper notes that early attempts to control the transducer array with a Arduino Mega failed, and that the team had to switch over to a FPGA. With their current signal generator stage, the researchers are able to rotate the specimen by 5° angles.
Interested in learning more about acoustic levitation? University of Bristol research scientist
Asier Marzo gave a talk on the subject at Hackaday Belgrade in 2018
that you won’t want to miss. | 6 | 1 | [
{
"comment_id": "8111454",
"author": "Gogu",
"timestamp": "2025-03-22T19:19:18",
"content": "Wonder if that insect goes deaf…lol",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8111493",
"author": "Tim",
"timestamp": "2025-03-23T00:18:02",
... | 1,760,371,600.069554 | ||
https://hackaday.com/2025/03/22/thanks-for-hackaday-europe/ | Thanks For Hackaday Europe! | Elliot Williams | [
"cons",
"Hackaday Columns"
] | [
"2025 Hackaday Europe",
"Culture"
] | We just got back from Hackaday Europe last weekend, and we’re still coming down off the high. It was great to be surrounded by so many crazy, bright, and crazy-bright folks all sharing what they are pouring their creative energy into.
The talks were great
, and the discussions and impromptu collaborations have added dramatically to our stack of to-do projects. (Thanks?) Badges were hacked, stories were shared, and a good time was had by all.
At the event, we were approached by someone who wanted to know if we could replicate something like Hackaday Europe in a different location, one where there just isn’t as vibrant a hacking scene. And the answer, of course, was maybe, but probably not.
It’s not that we don’t try to put on a good show, bring along fun schwag, and schedule up a nice location. But it’s the crowd of people who attend who make a Hackaday event a Hackaday event. Without you all, it just wouldn’t work.
So in that spirit, thanks to everyone who attended, and who brought along their passions and projects! It was great to see you all, and we’ll do it again soon.
This article is part of the Hackaday.com newsletter, delivered every seven days for each of the last 200+ weeks. It also includes our favorite articles from the last seven days that you can see on
the web version of the newsletter
.
Want this type of article to hit your inbox every Friday morning?
You should sign up
! | 10 | 6 | [
{
"comment_id": "8111414",
"author": "Sebastian",
"timestamp": "2025-03-22T16:04:16",
"content": "It was a good event, well put together and organized. Only thing i’d change is the stage, it was sometimes difficult to follow a presentation with all the loud conversation of the hackers doing their pr... | 1,760,371,599.847277 | ||
https://hackaday.com/2025/03/22/the-fastest-ms-dos-gaming-pc-ever/ | The Fastest MS-DOS Gaming PC Ever | Maya Posch | [
"Retrocomputing"
] | [
"benchmark",
"ISA cards",
"ms-dos"
] | After [Andy]’s discovery of an old ISA soundcard at his parents’ place that once was inside the family PC, the onset of a wave of nostalgia for those old-school sounds drove him off the deep end. This is how we get [Andy] building
the fastest MS-DOS gaming system ever
, with ISA slot and full hardware compatibility. After some digging around, the fastest CPU for an Intel platform that still retained ISA compatibility turned out to be Intel’s 4th generation Core series i7-4790K CPU, along with an H81 chipset-based MiniITX mainboard.
Of note is that ISA slots on these newer boards are basically unheard of outside of niche industrial applications, ergo [Andy] had to tap into the
LPC
(low pin count) debug port & hunt down the LDRQ signal on the mainboard. LPC is a very compact version of the ISA bus that works great with ISA adapter boards, specially an LPC to ISA adapter like [Andy]’s
dISAppointment board
as used here.
A PCIe graphics card (NVidia 7600 GT, 256 MB VRAM), ISA soundcard, dodgy PSU and a SATA SSD were added into a period-correct case. After this Windows 98 was installed from a USB stick within a minute using [Eric Voirin]’s
Windows 98 Quick Install
. This gave access to MS-DOS and enabled the first tests, followed by benchmarking.
Benchmarking MS-DOS on a system this fast turned out to be somewhat messy with puzzling results. The reason for this was that the BIOS default settings under MS-DOS limited the CPU to non-turbo speeds. After this the system turned out to be actually really quite fast at MS-DOS (and Windows 98) games, to nobody’s surprise.
If you’d like to run MS-DOS on relatively modern hardware with a little less effort, you could always
pick up a second-hand ThinkPad and rip through some
Descent
. | 28 | 9 | [
{
"comment_id": "8111371",
"author": "paulvdh",
"timestamp": "2025-03-22T12:11:08",
"content": "Euhm, LPC is pretty much a serialized version of the ISA bus, not of the PCI bus as mentioned above.https://en.wikipedia.org/wiki/Low_Pin_Count",
"parent_id": null,
"depth": 1,
"replies": [
... | 1,760,371,600.183062 | ||
https://hackaday.com/2025/03/22/biosynthesis-of-polyester-amides-in-engineered-escherichia-coli/ | Biosynthesis Of Polyester Amides In Engineered Escherichia Coli | Maya Posch | [
"Science"
] | [
"biopolymer",
"E coli"
] | Polymers are one of the most important elements of modern-day society, particularly in the form of plastics. Unfortunately most common polymers are derived from fossil resources, which not only makes them a finite resource, but is also problematic from a pollution perspective. A potential alternative being researched is that of biopolymers, in particular those produced by microorganisms such as everyone’s favorite bacterium
Escherichia coli
(
E. coli
).
These bacteria were the subject of a recent biopolymer study by [Tong Un Chae] et al., as
published
in
Nature Chemical Biology
(paywalled, break-down
on Arstechnica
).
By genetically engineering
E. coli
bacteria to use one of their survival energy storage pathways instead for synthesizing long chains of polyester amides (PEAs), the researchers were able to make the bacteria create long chains of mostly pure PEA. A complication here is that this modified pathway is not exactly picky about what amino acid monomers to stick onto the chain next, including metabolism products.
Although using genetically engineered bacteria for the synthesis of products on an industrial scale isn’t uncommon (see e.g. the synthesis of insulin), it would seem that biosynthesis of plastics using our prokaryotic friends isn’t quite ready yet to graduate from laboratory experiments. | 8 | 5 | [
{
"comment_id": "8111356",
"author": "Dan",
"timestamp": "2025-03-22T10:29:21",
"content": "This seems really neat… though I’m imagining people getting food poisoning and vomiting up plastic pellets! … actually that might be an improvement!I’m not that familiar with PEA but it looks to be very biode... | 1,760,371,599.799601 | ||
https://hackaday.com/2025/03/21/a-cute-handheld-gaming-device-that-you-can-build-in-an-altoids-tin/ | A Cute Handheld Gaming Device That You Can Build In An Altoids Tin | Lewin Day | [
"handhelds hacks",
"Raspberry Pi"
] | [
"altoids tin",
"handheld",
"raspberry pi"
] | The MintyPi was a popular project that put a Raspberry Pi inside an Altoids tin to make a pocketable gaming handheld. Unfortunately, it’s not the easiest build to replicate anymore, but [jackw01] was still a fan of the format. Thus was born the Pi Tin—
a clamshell handheld for portable fun
!
Neat, huh? More pocket-sized than the Game Boy Pocket.
The build is based around the Raspberry Pi Zero 2W, which packs more power than the original Pi Zero into the same compact form factor. It’s combined with a 320 x 240 TFT LCD screen and a 2000 mAh lithium-polymer battery which provides power on the go.
There are also a pair of custom PCBs used to lace everything together, including the action buttons, D-pad, and power management hardware. Depending on your tastes, you have two main enclosure options. You can use the neat 3D printed clamshell seen here in beautiful teal, or you can go with the classic Altoids tin build—just be careful when you’re cutting it to suit! Files can be found
on GitHub
for the curious.
We love a good handheld project around these parts; it’s particularly awesome how much gaming you can fit in your pocket given
the magic of the Raspberry Pi and modern emulation
. If you’re cooking up your own little retro rig, don’t hesitate to
let us know! | 10 | 5 | [
{
"comment_id": "8111300",
"author": "Joshua",
"timestamp": "2025-03-22T05:50:33",
"content": "By the looks, it reminds me of the 1&1 Pocket Web that had been heavily advertised in my country some 20 years ago.https://de.wikipedia.org/wiki/Pocket_Web",
"parent_id": null,
"depth": 1,
"rep... | 1,760,371,599.939082 | ||
https://hackaday.com/2025/03/21/producing-syngas-from-co2-and-sunlight-with-direct-air-capture/ | Producing Syngas From CO2 And Sunlight With Direct Air Capture | Maya Posch | [
"green hacks",
"Science"
] | [
"carbon dioxide",
"syngas"
] | The prototype DACCU device for producing syngas from air. (Credit: Sayan Kar, University of Cambridge)
There is more carbon dioxide (CO
2
) in the atmosphere these days than ever before in human history, and while it would be marvelous to use these carbon atoms for something more useful, capturing CO
2
directly from the air isn’t that easy. After capturing it would also be great if you could do something more with it than stuff it into a big hole. Something like producing syngas (CO + H
2
) for example,
as demonstrated
by researchers at the University of Cambridge.
Among the improvements
claimed in the paper
as published in
Nature Energy
for this direct air capture and utilization (DACCU) approach are that it does not require pure CO
2
feedstock, but will adsorb it directly from the air passing over a bed of solid silica-amine. After adsorption, the CO
2
can be released again by exposure to concentrated light. Following this the conversion to syngas is accomplished by passing it over a second bed consisting of silica/alumina-titania-cobalt bis(terpyridine), that acts as a photocatalyst.
The envisioned usage scenario would be CO2 adsorption during the night, with concentrated solar power releasing it the day with subsequent production of syngas. Inlet air would be passed only over the adsorption section before switching the inlet off during the syngas generating phase. As a lab proof-of-concept it seems to work well, with outlet air stripped from virtually all CO
2
and very high conversion ratio from CO
2
to syngas.
Syngas
has historically been used as a replacement for gasoline, but is also used as a source of hydrogen (e.g. steam reformation (SMR) of natural gas) where it’s used for reduction of iron ore, as well as the production of methanol as a precursor to many industrial processes. Whether this DACCU approach provides a viable alternative to SMR and other existing technologies will become clear once this technology moves from the lab into the real world.
Thanks to [Dan] for the tip. | 17 | 6 | [
{
"comment_id": "8111340",
"author": "Foldi-One",
"timestamp": "2025-03-22T09:21:08",
"content": "Seems like a very long way to go before a concept like this can be engineered and scaled to something of practical value but I do like the approach conceptually. Though I’m not convinced the solar energ... | 1,760,371,600.019143 | ||
https://hackaday.com/2025/03/21/moving-software-down-to-hardware/ | Moving Software Down To Hardware | Bryan Cockfield | [
"hardware"
] | [
"communications",
"counter",
"hardware",
"i2c",
"programming",
"shift register"
] | In theory, any piece of software could be built out of discrete pieces of hardware, provided there are enough transistors, passive components, and time available. In general, though, we’re much more likely to reach for a programmable computer or microcontroller for all but the simplest tasks for several reasons: cost, effort, complexity, economics, and sanity. [Igor Brichkov] was working with I2C and decided that he wanted to see just where this line between hardware and software should be
by implementing this protocol itself directly with hardware
.
One of the keys to “programming” a communications protocol in hardware is getting the timing right, the first part of which is initializing communications between this device and another on the bus. [Igor] is going to be building up the signal in parts and then ORing them together. The first part is a start condition, generated by one oscillator and a counter. This also creates a pause, at which point a second oscillator takes over and sends data out. The first data needed for I2C is an address, which is done with a shift register and a counter pre-set to send the correct bits out on the communications lines.
To build up the rest of the signal, including data from the rotary encoder [Igor] is using for his project, essentially sets of shift registers and counters are paired together to pass data out through the I2C communications lines in sequence. It could be thought of that the main loop of the hardware program is a counter, which steps through all the functions sequentially, sending out data from the shift registers one by one.
We saw a similar project over a decade ago
, but rather than automating the task of sending data on I2C it allowed the user to key in data manually instead. | 12 | 5 | [
{
"comment_id": "8111255",
"author": "Paul",
"timestamp": "2025-03-22T00:43:10",
"content": "If you think this is wild, have a look at how a Model 15 teletype decodes the incoming serial bitstream inrealhardware. That is: Without a single semiconductor.",
"parent_id": null,
"depth": 1,
... | 1,760,371,600.116042 | ||
https://hackaday.com/2025/03/21/turning-a-kombucha-bottle-into-a-plasma-tube/ | Turning A Kombucha Bottle Into A Plasma Tube | Lewin Day | [
"High Voltage"
] | [
"high voltage",
"plasma",
"plasma tube"
] | Kombucha! It’s a delicious fermented beverage that is kind to your digestive system and often sold in glass bottles. You don’t just have to use those bottles for healthy drinks, though. As [Simranjit Singh] demonstrates, you can also use them
to create your very own plasma tube.
[Simranjit’s] build begins with a nice large 1.4-liter kombucha bottle from the Synergy brand. To make the plasma tube nicely symmetrical, the bottle had its original spout cut off cleanly with a hot wire, with the end then sealed with a glass cap. Electrodes were installed in each end of the tube by carefully drilling out the glass and installing small bolts. They were sealed in place with epoxy laced with aluminium oxide in order to improve the dielectric strength and aid the performance of the chamber. A vacuum chamber was then used to evacuate air from inside the chamber. Once built, [Simranjit] tested the bottle with high voltage supplied from a flyback transformer, with long purple arcs flowing freely through the chamber.
A plasma tube may not be particularly useful beyond educational purposes, but it does look very cool. We do enjoy a nice
high-voltage project
around these parts, after all. | 9 | 3 | [
{
"comment_id": "8111239",
"author": "El Gru",
"timestamp": "2025-03-21T22:17:50",
"content": "So, the beverage is the important part here? Must be Kombucha, but the material of the bottle is irrelevant? Interesting.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_... | 1,760,371,599.889631 | ||
https://hackaday.com/2025/03/21/building-a-handheld-pong-game/ | Building A Handheld Pong Game | Lewin Day | [
"classic hacks",
"Games"
] | [
"3D printed enclosure",
"ESP32",
"handheld",
"pong"
] | Pong was one of the first video games to really enter the public consciousness. While it hasn’t had the staying power of franchises like
Zelda
or
Call of Duty,
it nonetheless still resonates with gamers today. That includes [Arnov Sharma], who put together
this neat handheld version using modern components.
An ESP32 development board serves as the brains of the operation. Capable of operating at many hundreds of megahertz, it has an excessive amount of power for an application as simple as this. Nonetheless, it’s cheap, and it gets the job done. It’s paired with an SSD1306 OLED screen of 124 x 32 resolution. That might not sound like much, but it’s plenty when you’re just drawing two paddles and a ball bouncing between them. Control is via a pair of SMD push buttons for a nice responsive feel.
What’s really neat, though, is the presentation. [Arnov] wrapped the electronics in a neat bean-shaped housing that vaguely apes game controllers of the 16-bit era. Indeed, [Arnov] explains that it was inspired by the Sega Genesis specifically. It looks great with the black PCBs integrated so nicely with the bright orange 3D printed components, and looks quite comfortable to use, too.
It might be a simple project, but it’s done rather well. Just by thinking about color choices and how to assemble the base components, [Arnov] was able to create an attractive and functional game that’s a lot more eye catching than some random boards thrown in an old project box. Indeed, we’ve featured stories on
advanced FR4/PCB construction techniques before, too
. Meanwhile, if you’re creating your own projects with similar techniques, don’t hesitate to
let us know! | 3 | 3 | [
{
"comment_id": "8111213",
"author": "CJay",
"timestamp": "2025-03-21T20:28:33",
"content": "I dunno, people still building and playing after 53 years seems like it’s definitely got some longevity",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8111238",
"a... | 1,760,371,599.756166 | ||
https://hackaday.com/2025/03/21/high-frequency-food-better-cutting-with-ultrasonics/ | High Frequency Food: Better Cutting With Ultrasonics | Lewin Day | [
"Featured",
"Interest",
"Misc Hacks",
"Slider"
] | [
"cutting",
"food",
"ultrasonic",
"ultrasound"
] | You’re cutting yourself a single slice of cake. You grab a butter knife out of the drawer, hack off a moist wedge, and munch away to your mouth’s delight. The next day, you’re cutting forty slices of cake for the whole office. You grab a large chef’s knife, warm it with hot water, and cube out the sheet cake without causing too much trauma to the icing. Next week, you’re starting at your cousin’s bakery. You’re supposed to cut a few thousand slices of cake, week in, week out. You suspect your haggardly knifework won’t do.
In the home kitchen, any old knife will do the job when it comes to slicing cakes, pies, and pastries. When it comes to commercial kitchens, though, presentation is everything and perfection is the bare minimum. Thankfully, there’s a better grade of cutting tool out there—and it’s more high tech than you might think.
Shake It
Knives are very good at cutting food into distinct separate pieces. However, they have one major problem—food is sticky, and so are they. If you’ve ever cut through a cheesecake, you’ve seen this in action. Unless you’re very careful and deft with your slicing, the cake tends to grip the blade of the knife as it comes through. Try as you might, you’re almost always going to leave some marred edges unless you work very slowly.
While most home chefs and cafes can turn a blind eye to these sorts of things, that’s not the case in the processed food industry. For one thing, consumers expect each individually-packed morsel of food to be as cosmetically perfect as the last. For another, cutting processes have to be robust to work at speed. A human can compensate as they cut, freeing the blade from sticking and fettling the final product to hide their mistakes. Contrast that to a production line that slices ice cream bars from a sheet all day. All it takes is one stuck piece to completely mess up the production line and ruin the product.
This is where ultrasonic food processing comes in. Ultrasonic cutting blades exist for one primary reason—they enable the cutting of all kinds of different foods without sticking, squashing, or otherwise marring the food. These blades most commonly find themselves used in processed food production lines, where a bulk material must be cut into individual bars or slices for later preparation or packaging.
It’s quite something to watch these blades in action. Companies like Dukane and MeiShun have demo videos that show the uncanny ability of their products to slice through even the stickiest foods without issue. You can watch cheesecakes get evenly sectored into perfect triangular slices, or a soft brie cheese being sliced without any material being left on the blade. The technique works on drier materials too—it’s possible to cut perfectly nice slices of bread with less squishing and distortion using ultrasonic blades. Even complex cakes,
like the vanilla slice
, with layers of stiff pastry and smooth custard, can be cut into neat polygons with appropriate ultrasonic tooling.
The mechanism of action is well-understood. An ultrasonic cutting blade is formally known as a sonotrode, and is still sharpened to an edge to do its job. However, where it varies from a regular blade is that it does not use mere pressure to slice through the target material. Instead, transducers in the sonotrode vibrate it at an ultrasonic frequency—beyond the range of human hearing, typically from 20 kHz to 40 kHz. When the sonotrode comes into contact with the material, the high-frequency vibrations allow it to slice through the material without sticking to it. Since the entire blade is vibrating, it continues to not stick as it slides downwards, allowing for an exceptionally clean cut.
Generally, the ultrasonic sonotrode is paired with a motion platform to move the food precisely through the cutting process, and an actuator to perform the cutting action itself. However, there are also
handheld ultrasonic knives
that can be purchased for those looking to use the same technique manually.
Just don’t expect to get this hardware cheap. On Chinese industrial reseller websites, ultrasonic cutting rigs tend to start in the five-figure range, and go up from there. Prices can quickly increase for larger rigs, those with conveyors, or with more advanced capabilities. If you want a more specialized sonotrode or need to swap out different tooling for different target materials, expect to pay a suitable further sum for that capability, too. One saving grace, however, is that the sonotrode tooling doesn’t quite wear in the same way as a normal cutting blade, since it’s not solely relying on its sharpness to get a clean cut. These devices still need to be cleaned and maintained, but they don’t dull in the same way a simple knife does.
The technique isn’t solely applied to the food industry. The same techniques work for many other difficult-to-cut materials, like rubber. The technique can also be applied to various textiles or plastic materials, too.
In some cases
, the sonotrode can generate enough heat as it cuts through the materials to melt and seal the edges of the material it’s cutting through.
If you’re simply looking to cut some cake at home, this technique might be a little overly advanced for you. At the same time, there’s nothing stopping you from rigging up some transducers with a blade and a DIY CNC platform seeing what you can achieve. If you want the most perfectly cubed sheet cake at your next office party, this might just be the technology you’re looking for. | 36 | 17 | [
{
"comment_id": "8111179",
"author": "Ostracus",
"timestamp": "2025-03-21T17:43:28",
"content": "A step up from those vibrating knives used to carve the thanksgiving turkey.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8111189",
"author": "Jeremiah McCar... | 1,760,371,600.2561 | ||
https://hackaday.com/2025/03/21/hackaday-podcast-episode-313-capacitor-plague-wireless-power-and-tiny-everything/ | Hackaday Podcast Episode 313: Capacitor Plague, Wireless Power, And Tiny Everything | Jenny List | [
"Hackaday Columns",
"Podcasts"
] | [
"Hackaday Podcast"
] | We’re firmly in Europe this week on the Hackaday podcast, as Elliot Williams and Jenny List are freshly returned from Berlin and Hackaday Europe. A few days of mingling with the Hackaday community, going through mild panic over badges and SAOs, and enjoying the unique atmosphere of that city.
After discussing the weekend’s festivities we dive right into the hacks, touching on the coolest of thermal cameras, wildly inefficient but very entertaining wireless power transfer, and a restrospective on the capacitor plague from the early 2000s. Was it industrial espionage gone wrong, or something else? We also take a moment to consider spring PCB cnnectors, as used by both one of the Hackaday Europe SAOs, and a rather neat PCB resistance decade box, before looking at a tryly astounding PCB blinky that sets a new miniaturisation standard.
In our quick roundup the standouts are a 1970s British kit synthesiser and an emulated 6502 system written in shell script, and in the can’t-miss section we look at a new contender fro the smallest microcontroller, and the posibility that a century of waste coal ash may conceal a fortune in rare earth elements.
Follow the link below, to listen along!
Want the podcast in MP3?
Get it in MP3
!
Where to Follow Hackaday Podcast
Places to follow Hackaday podcasts:
iTunes
Spotify
Stitcher
RSS
YouTube
Check
out our Libsyn landing page
Episode 312 Show Notes:
What’s that Sound?
If you know what that sound was, and we think you probably do,
put your name down here to be in the drawing for the t-shirt
.
Interesting Hacks of the Week:
The Capacitor Plague Of The Early 2000s
Make Your Cheap Thermal Camera Into A Microscope
Transmitting Wireless Power Over Longer Distances
A Decade Resistance Box From PCBs
World’s Smallest Blinky, Now Even Smaller
Writing A GPS Receiver From Scratch
Quick Hacks:
Elliot’s Picks:
Reviving A Maplin 4600 DIY Synthesizer From The 1970s
Make Fancy Resin Printer 3D Models FDM-Friendly
Chemistry Meets Mechatronics In This Engaging Art Piece
Current Mirrors Tame Common Mode Noise
Speeding Up Your Projects With Direct Memory Access
Jenny’s Picks:
Pick Up A Pebble Again
Turning Down The Noise On SMPS
A 6502, In The Shell
Repairing A Kodak Picture Maker Kiosk
Can’t-Miss Articles:
Ask Hackaday: What Would You Do With The World’s Smallest Microcontroller?
From The Ashes: Coal Ash May Offer Rich Source Of Rare Earth Elements | 3 | 2 | [
{
"comment_id": "8111211",
"author": "make piece not war",
"timestamp": "2025-03-21T20:03:09",
"content": "Just downloaded 3 copies of the podcast (using AntennaPod), yet only one is playable (the second one). But all of them got the description.",
"parent_id": null,
"depth": 1,
"replies... | 1,760,371,600.317801 | ||
https://hackaday.com/2025/03/21/benchtop-haber-bosch-makes-ammonia-at-home/ | Benchtop Haber-Bosch Makes Ammonia At Home | Dan Maloney | [
"chemistry hacks"
] | [
"ammonia",
"catalyst",
"glassware",
"Haber-Bosch",
"lab",
"sulfuric acid",
"zinc"
] | Humans weren’t the first organisms on this planet to figure out how to turn the abundance of nitrogen in the atmosphere into a chemically useful form; that honor goes to some microbes that learned how to make the most of the primordial soup they called home. But to our credit, once [Messrs. Haber and Bosch] figured out how to make ammonia from thin air, we really went gangbusters on it, to the tune of 8 million tons per year of the stuff.
While it’s not likely that
[benchtop take on the Haber-Bosch process demonstrated by [Marb’s lab]
will turn out more than the barest fraction of that, it’s still pretty cool to see the ammonia-making process executed in such an up close and personal way.
The industrial version of Haber-Bosch
uses heat, pressure, and catalysts to overcome the objections of diatomic nitrogen to splitting apart and forming NH
3
; [Marb]’s version does much the same, albeit at tamer pressures.
[Marb]’s process starts with hydrogen made by dripping sulfuric acid onto zinc strips and drying it through a bed of silica gel. The dried hydrogen then makes its way into a quartz glass reaction tube, which is heated by a modified camp stove. Directly above the flame is a ceramic boat filled with catalyst, which is a mixture of aluminum oxide and iron powder; does that sound like the recipe for thermite to anyone else?
A vial of Berthelot’s reagent, which [Marb] used in
his recent blood ammonia assay
, indicates when ammonia is produced. To start a run, [Marb] first purges the apparatus with nitrogen, to prevent any hydrogen-related catastrophes. After starting the hydrogen generator and flaring off the excess, he heats up the catalyst bed and starts pushing pure nitrogen through the chamber. In short order the Berthelot reagent starts turning dark blue, indicating the production of ammonia.
It’s a great demonstration of the process, but what we like about it is the fantastic tips about building lab apparatus on the cheap. Particularly the idea of using hardware store pipe clamps to secure glassware; the mold-it-yourself silicone stoppers were cool too. | 24 | 6 | [
{
"comment_id": "8111138",
"author": "strawberrymortallyb0bcea48e7",
"timestamp": "2025-03-21T15:38:50",
"content": "For how long will this kind of content be legal on Youtube?",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8111152",
"author": "macsi... | 1,760,371,600.83516 | ||
https://hackaday.com/2025/03/21/this-week-in-security-the-github-supply-chain-attack-ransomware-decryption-and-paragon/ | This Week In Security: The Github Supply Chain Attack, Ransomware Decryption, And Paragon | Jonathan Bennett | [
"Hackaday Columns",
"News",
"Security Hacks"
] | [
"Github Actions",
"Paragon",
"supply chain attack",
"This Week in Security"
] | Last Friday Github saw
a supply chain attack hidden in a popular Github Action
. To understand this, we have to quickly cover Continuous Integration (CI) and Github Actions. CI essentially means automatic builds of a project. Time to make a release? CI run. A commit was pushed? CI run. For some projects, even pull requests trigger a CI run. It’s particularly handy when the project has a test suite that can be run inside the CI process.
Doing automated builds may sound straightforward, but the process includes checking out code, installing build dependencies, doing a build, determining if the build succeeded, and then uploading the results somewhere useful. Sometimes this even includes making commits to the repo itself, to increment a version number for instance. For each step there are different approaches and interesting quirks for every project. Github handles this by maintaining a marketplace of “actions”, many of which are community maintained. Those are reusable code snippets that handle many CI processes with just a few options.
One other element to understand is “secrets”. If a project release process ends with uploading to an AWS store, the process needs an access key. Github stores those secrets securely, and makes them available in Github Actions. Between the ability to make changes to the project itself, and the potential for leaking secrets, it suddenly becomes clear why it’s very important not to let untrusted code run inside the context of a Github Action.
And this brings us to what happened last Friday. One of those community maintained actions,
tj-actions/changed-files
, was modified to pull an obfuscated Python script and run it. That code dumps the memory of the Github runner process, looks for anything there tagged with
isSecret
, and writes those values out to the log. The log, that coincidentally, is world readable for public repositories, so printing secrets to the log exposes them for anyone that knows where to look.
Researchers at
StepSecurity have been covering this
, and have
a simple search string
to use:
org:changeme tj-actions/changed-files Action
. That just looks for any mention of the compromised action. It’s unclear whether the compromised action was embedded in any other popular actions. The recommendation is to search recent Github Action logs for any mention of
changed-files
, and start rotating secrets if present.
Linux Supply Chain Research
The folks at Fenrisk were also thinking about supply chain attacks recently, but specifically in
how Linux distributions are packaged
. They did find
a quartet of issues in Fedora’s Pagure web application
, which is used for source code management for Fedora packages. The most severe of them is an argument injection in the logging function, allowing for arbitrary file write.
The
identifier
option is intended to set the branchname for a request, but it can be hijacked in a request, injecting the output flag:
http://pagure.local/test/history/README.md?identifier=--output=/tmp/foo.bar
. That bit of redirection will output the Git history to the file specified. Git history consists of a git hash, and then the short commit message. That commit message has very little in the way of character scrubbing, so Bash booleans like
||
can be used to smuggle a command in. Add the cooked commit to your local branch of something, query the URL to write the file history to your
.bashrc
file, and then attempt to SSH in to the Pagure service. The server does the right thing with the SSH connection, refusing to give the user a shell, but not before executing the code dropped into the
.bashrc
file. This one was disclosed in April 2024, and was fixed within hours of disclosure by Red Hat.
Pagure was not the only target, and Fenrisk researchers also discovered a critical vulnerability in OpenSUSE’s Open Build Service. It’s actually similar to the Fedora Pagure issue. Command options can be injected into the wget command used to download the package source file. The
--output-document
argument can be used to write arbitrary data to a file in the user’s home directory, but there isn’t an obvious path to executing that file. There are likely several ways this could be accomplished, but the one chosen for this Proof of Concept (PoC) was writing a
.proverc
file in the home directory. Then a second wget argument is injected, using
--use-askpass
to trigger the
prove
binary. It loads from the local rc file, and we have arbitrary shell code execution. The OpenSUSE team had fixes available and rolled out within a few days of the private disclosure back in June of 2024.
Breaking Ransomware Encryption
What do you do when company data is hit with Akira ransomware, and the backups were found wanting? If you’re [Yohanes Nugroho], apparently
you roll up your sleeves and get to work
. This particular strain of Akira has a weakness that made decryption and recovery seemingly easy. The encryption key was seeded by the current system time, and [Yohanes] had both system logs and file modification timestamps to work with. That’s the danger of using timestamps for random seeds. If you know the timestamp, the pseudorandom sequence can be derived.
It turns out, it wasn’t quite that easy. This strain of Akira actually used four separate nanosecond scale time values in determining the per-file encryption key. Values we’ll call t3 and t4 are used to seed the encryption used for the first eight bytes of each file. If there’s any hope of decrypting these files, those two values will have to be found first. Through decompiling the malware binaries, [Yohanes] knew that the malware process would start execution, then run a fixed amount of code to generate the t3 key, and a fixed amount of code before generating the t4 key. In an ideal world, that fixed code would take a fixed amount of time to run, but multi-core machines, running multi-threaded operations on real hardware will introduce variations in that timing.
The real-world result is a range of possible time offsets for both those values. Each timestamp from the log results in about 4.5 quadrillion timestamp pairs. Because the timing is more known, once t3 and t4 are discovered, finding t1 and t2 is much quicker. There are some fun optimizations that can be done, like generating a timestamp to pseudorandom value lookup table. It works well ported to CUDA, running on an RTX 4090. In the end, brute-forcing a 10 second slice of timestamps cost about $1300 dollars when renting GPUs through a service like vast.ai. The source code that made this possible isn’t pretty, but [Yohanes] has made it all available if you want to attempt the same trick.
Github and Ruby-SAML — The Rest of the Story
Last week we briefly talked about Github’s discovery of the multiple parser problem in Ruby-SAML, leading to authentication bypass. Researchers at Portswigger were also working on this vulnerability, and have
their report out with more details
. One of those details is that while Github had already moved away from using this library, Gitlab Enterprise had not. This was a real vulnerability on Gitlab installs, and if your install is old enough, maybe it still is.
The key here is a CDATA section wrapped in an XML comment section is only seen by one of the parsers. Include two separate assertion blocks, and you get to drive right through the difference between the two parsers.
Paragon
There’s a new player in the realm of legal malware. Paragon has
reportedly targeted about 90 WhatsApp users
with a zero-click exploit, using a malicious PDF attachment to compromise Android devices. WhatsApp has mitigated this particular vulnerability on the server side.
It’s interesting that apparently there’s something about the process of adding the target user to the WhatsApp group that was important to making the attack work. Paragon shares some similarities with NSO Group, but maintains that it’s being more careful about who those services are being offered to.
Bits and Bytes
We have a pair of local privilege escalation attacks. This is useful when an attacker has unprivileged access to a machine, but can use already installed software to get further access. The first is
Google’s Web Designer
, that starts a debug port, and exposes an account token and file read/right to the local system. The other is
missing quotation marks in Plantronics Hub
, which leads to the application attempting to execute
C:\Program.exe
before it descends into
Program Files
to look for the proper location.
This is your reminder, from Domain Guard, to
clean up your DNS records
. I’ve now gone through multiple IP address changes of my “static” IP Addresses. At the current rate of IPv4 exhaustion, those IPs are essentially guaranteed to be given out to somebody else. Is it a problem to have dangling DNS records? It’s definitely not a good situation, because it enables hacks from cross-site scripting vulnerabilities, to cookie stealing, to potentially defeating domain verification schemes with the errant subdomain.
MacOS has quite a fine history of null-pointer dereference vulnerabilities. That’s when a pointer is still set to NULL, or 0, and the program errantly tries to access that memory location. It used to be that a clever attacker could actually claim memory location 0, and take advantage of the bogus dereference. But MacOS put an end to that technique in a couple different ways, the most effective being disallowing 32 bit processes altogether in recent releases. It seems that
arbitrary code execution on MacOS as result of a NULL Pointer Dereference is a thing of the past
. And yes, we’re quite aware that this statement means that somehow, someone will figure out a way to make it happen.
And Finally, watchTowr is back with
their delightful blend of humor and security research
. This time it’s a chain of vulnerabilities leading to an RCE in Kentico, a proprietary web Content Management System. This vulnerability has one of my least favorite data formats, SOAP XML. It turns out Kentico’s user authentication returns an empty string instead of a password hash when dealing with an invalid username. And that means you can craft a SOAP authenticaiton token with nothing more than a valid nonce and timestamp. Whoops. The issue was fixed in a mere six days, so good on Kentico for that. | 4 | 2 | [
{
"comment_id": "8111095",
"author": "Greg A",
"timestamp": "2025-03-21T14:15:02",
"content": "CI is neat but it has always boggled my mind that people want to do so much of it in the wild instead of cloistered. i wouldn’t want someone else’s CI running on my server and i certainly wouldn’t want my... | 1,760,371,600.773175 | ||
https://hackaday.com/2025/03/21/aluminum-business-cards-make-viable-pcb-stencils/ | Aluminum Business Cards Make Viable PCB Stencils | Lewin Day | [
"PCB Hacks",
"Tool Hacks"
] | [
"aluminium",
"aluminium business card",
"pcb",
"stencil"
] | [Mikey Sklar] had a problem—namely, running low on the brass material typically used for making PCB stencils. Thankfully, a replacement material was not hard to find. It turns out
you can use aluminum business card blanks to make viable PCB stencils.
Why business card blanks? They’re cheap, for a start—maybe 15 cents each in quantity. They’re also the right thickness, at just
0.8 mm
0.18 mm, and they’re flat, unlike rolled materials that can tend to flip up when you’re trying to spread paste. They’re only good for small PCBs, of course, but for many applications, they’ll do just fine.
To cut these, you’ll probably want a laser cutter. [Mikey] was duly equipped in that regard already, which helped. Using a 20 watt fiber laser at a power of 80%, he was able to get nice accurate cuts for the stencils. Thanks to the small size of the PCBs in question, the stencils for three PCBs could be crammed on to a single card.
If you’re not happy with your existing PCB stencil material, you might like to try these aluminium blanks on for size.
We’ve covered other stenciling topics before, too. | 25 | 6 | [
{
"comment_id": "8111065",
"author": "jbx",
"timestamp": "2025-03-21T13:08:25",
"content": "Aluminum ?Then :HelumLithumSodumPotassumSilicumGermanumRadumUranumPlutonum…",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8111068",
"author": "Queeg",
... | 1,760,371,600.732976 | ||
https://hackaday.com/2025/03/21/cheap-endoscopic-camera-helps-automate-pressure-advance-calibration/ | Cheap Endoscopic Camera Helps Automate Pressure Advance Calibration | Dan Maloney | [
"3d Printer hacks"
] | [
"calibration",
"endoscope",
"extrusion",
"image analysis",
"klipper",
"machine vision",
"pressure advance"
] | The difference between 3D printing and
good
3D printing comes down to attention to detail. There are so many settings and so many variables, each of which seems to impact the other to a degree that can make setting things up a maddening process. That makes anything that simplifies the process, such as
this computer vision pressure advance attachment
, a welcome addition to the printing toolchain.
If you haven’t run into the term “pressure advance” for FDM printing before, fear not; it’s pretty intuitive. It’s just a way to compensate for the elasticity of the molten plastic column in the extruder, which can cause variations in the amount of material deposited when the print head acceleration changes, such as at corners or when starting a new layer.
To automate his pressure advance calibration process, [Marius Wachtler] attached one of those dirt-cheap endoscope cameras to the print head of his modified Ender 3, pointing straight down and square with the bed. A test grid is printed in a corner of the bed, with each arm printed using a slightly different pressure advance setting. The camera takes a photo of the pattern, which is processed by computer vision to remove the background and measure the thickness of each line. The line with the least variation wins, and the pressure advance setting used to print that line is used for the rest of the print — no blubs, no blebs.
We’ve seen
other pressure-advanced calibrators
before, but we like this one because it seems so cheap and easy to put together. True, it does mean sending images off to the cloud for analysis, but that seems a small price to pay for the convenience. And [Marius] is hopeful that he’ll be able to run the model locally at some point; we’re looking forward to that. | 27 | 7 | [
{
"comment_id": "8111053",
"author": "Arjan",
"timestamp": "2025-03-21T12:31:33",
"content": "Pressure advance on an Ender3 with its plastic wheels and cantilever Z-axis is like mounting Brembo disc brakes on the 4 wheels of an old Fiat panda. Cool that it can be done and a very nice proof of concep... | 1,760,371,600.898752 | ||
https://hackaday.com/2025/03/20/a-modern-take-on-the-etch-a-sketch/ | A Modern Take On The Etch A Sketch | Bryan Cockfield | [
"Toy Hacks"
] | [
"etch a sketch",
"IMU",
"intertial measurement",
"led",
"matrix",
"microcontroller",
"tilt-a-sketch"
] | The Etch A Sketch is a classic children’s toy resembling a picture frame where artwork can be made by turning two knobs attached to a stylus inside the frame. The stylus scrapes off an aluminum powder, creating the image which can then be erased by turning the frame upside down and shaking it, adding the powder back to the display. It’s completely offline and requires no batteries, but in our modern world those two things seem to be more requirements than when the Etch A Sketch was first produced in the 1960s.
Enter the Tilt-A-Sketch, a modern version of the classic toy
.
Rather than use aluminum powder for the display, the Tilt A Sketch replaces it with an LED matrix and removes the stylus completely. There are no knobs on this device to control the path of the LED either; a inertial measurement unit is able to sense the direction that the toy is tilted while a microcontroller uses that input to light up a series of LEDs corresponding to the direction of tilt. There are a few buttons on the side of the device as well which allow the colors displayed by the LEDs to change, and similar to the original toy the display can be reset by shaking.
The Tilt-A-Sketch was built by [devitoal] as part of an art display which allows the visitors to create their own art. Housed in a laser-cut wooden enclosure the toy does a faithful job of recreating the original. Perhaps unsurprisingly, the Etch A Sketch is a popular platform for various projects that we’ve seen before including
original toys modified with robotics to create the artwork
and
electronic recreations that use LED displays instead
in a way similar to this project. | 6 | 5 | [
{
"comment_id": "8110995",
"author": "Andrew",
"timestamp": "2025-03-21T05:21:58",
"content": "No thanks. Without the knobs it’s not an Etch-a-Sketch. And using a tilt sensor does not sound great at all. To me.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "81... | 1,760,371,600.675014 | ||
https://hackaday.com/2025/03/20/solar-power-logically/ | Solar Power, Logically | Al Williams | [
"Solar Hacks"
] | [
"solar power"
] | We’ve all seen the ads. Some offer “free” solar panels. Others promise nearly free energy if you just purchase a solar — well, solar system doesn’t sound right — maybe… solar energy setup. Many of these plans are dubious at best. You pay for someone to mount solar panels on your house and then pay them for the electricity they generate at — presumably — a lower cost than your usual source of electricity. But what about just doing your own set up? Is it worth it? We can’t answer that, but [Brian Potter] can help you
answer it for yourself
.
In a recent post, he talks about the rise of solar power and how it is becoming a large part of the power generation landscape. Interestingly, he presents graphs of things like the cost per watt of solar panels adjusted for 2023 dollars. In 1975, a watt cost over $100. These days it is about $0.30. So the price isn’t what slows solar adoption.
The biggest problem is the intermittent nature of solar. But how bad is that really? It depends. If you can sell power back to the grid when you have it to spare and then buy it back later, that might make sense. But it is more effective to store what you make for your own use.
That, however, complicates things. If you really want to go off the grid, you need enough capacity to address your peak demand and enough storage to meet demand over several days to account for overcast days, for example.
There’s more to it than just that. Read the post for more details. But even if you don’t want solar, if you enjoy seeing data-driven analysis, there is plenty to like here.
Building an effective
solar power system
is within reach of nearly anyone these days. Some of the problems with solar go away when you
put the cells in orbit
. Of course, that always raises new problems. | 86 | 13 | [
{
"comment_id": "8110979",
"author": "Leonardo",
"timestamp": "2025-03-21T03:45:49",
"content": "Where do you see the free solar panel ads?Never seen any of them.In witch country of the entire world do you see free solar panels? O_o",
"parent_id": null,
"depth": 1,
"replies": [
{
... | 1,760,371,601.190842 | ||
https://hackaday.com/2025/03/20/backyard-rope-tow-from-spare-parts/ | Backyard Rope Tow From Spare Parts | Bryan Cockfield | [
"Transportation Hacks"
] | [
"motor",
"rope tow",
"ski",
"ski lift",
"snow",
"snowblower",
"winter"
] | A few years ago, [Jeremy Makes Things] built a rope tow in his back yard so his son could ski after school. Since the lifts at the local hill closed shortly after schools let out, this was the only practical way for his son to get a few laps in during the week. It’s cobbled together from things that [Jeremy] had around the house, and since the original build it’s sat outside for a few years without much use. There’s been a lot more snow where he lives this year though,
so it’s time for a rebuild
.
The power source for the rope tow is an old gas-powered snowblower motor, with a set of rollers and pulleys for the rope made out of the back end of a razor scooter. Some polyurethane was poured around the old wheel hub so that the rope would have something to grip onto. The motor needed some sprucing up as well, from carburetor adjustment, fuel tank repairs, and some other pieces of maintenance before it could run again. With that out of the way it could be hoisted back up a tree at the top of the hill and connected to the long rope.
This isn’t the first time [Jeremy] has had to perform major maintenance on this machine either.
Three years ago it needed plenty of work
especially around the polyurethane wheel where [Jeremy] also had to machine a new wheel bearing in addition to all the other work that had to go into repairing it that time. From the looks of things though it’s a big hit with his son who zips right back up the hill after each ski run. Getting to the tops of ski runs with minimal effort has been a challenge of skiers and snowboarders alike for as long as the sport has been around,
and we’ve seen all kinds of unique solutions to that problem over the years
. | 9 | 5 | [
{
"comment_id": "8111001",
"author": "PeterC",
"timestamp": "2025-03-21T06:22:18",
"content": "Parents building something for their children make for some of the best projects featured on HaD.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8111036",
"autho... | 1,760,371,600.941904 | ||
https://hackaday.com/2025/03/19/modern-computings-roots-or-the-manchester-baby/ | Modern Computing’s Roots Or The Manchester Baby | Heidi Ulrich | [
"computer hacks",
"History"
] | [
"babbage",
"eniac",
"manchester",
"manchester baby",
"von neumann"
] | In the heart of Manchester, UK, a groundbreaking event took place in 1948: the first modern computer, known as the Manchester Baby, ran its very first program. The Baby’s ability to execute stored programs, developed with guidance from John von Neumann’s theory, marks it as a pioneer in the digital age. This fascinating chapter in computing history not only reshapes our understanding of technology’s roots but also highlights the incredible minds behind it. The original article, including a video transcript,
sits here at [TheChipletter]’s
.
So, what made this hack so special? The Manchester Baby, though a relatively simple prototype, was the first fully electronic computer to successfully run a program from memory. Built by a team with little formal experience in computing, the Baby featured a unique cathode-ray tube (CRT) as its memory store – a bold step towards modern computing. It didn’t just run numbers; it laid the foundation for all future machines that would use memory to store both data and instructions. Running a test to find the highest factor of a number, the Baby performed 3.5 million operations over 52 minutes. Impressive, by that time.
Despite criticisms that it was just a toy computer, the Baby’s significance shines through. It was more than just a prototype; it was proof of concept for
the von Neumann architecture
, showing us that computers could be more than complex calculators. While debates continue about whether it or
the ENIAC
should be considered the first true stored-program computer, the Baby’s role in the evolution of computing can’t be overlooked. | 15 | 9 | [
{
"comment_id": "8110698",
"author": "David",
"timestamp": "2025-03-19T23:54:37",
"content": "The 1998 rebuild included a world-wide programming contest, with the winner having the privilege of having his code run on the actual replica.The winner won on pure style points: It was a simple count-down... | 1,760,371,601.27815 | ||
https://hackaday.com/2025/03/19/this-m5stack-game-is-surprisingly-addictive/ | This M5Stack Game Is Surprisingly Addictive | Jenny List | [
"Games"
] | [
"accelerometer",
"game",
"M5Stack"
] | For those of us lucky enough to have been at Hackaday Europe in Berlin, there was a feast of hacks at our disposal. Among them was
[Vladimir Divic]’s gradients game
, software for an M5Stack module which was definitely a lot of fun to play. The idea of the game is simple enough, a procedurally generated contour map is displayed on the screen, and the player must navigate a red ball around and collect as many green ones as possible. It’s navigated using the M5Stack’s accelerometer, which is what makes for the engaging gameplay. In particular it takes a moment to discover that the ball can be given momentum, making it something more than a simple case of ball-rolling.
Underneath the hood it’s an Arduino .ino file for the M5Stack’s ESP32, and thus shouldn’t present a particular challenge to most readers. Meanwhile the M5Stack with its versatile range of peripherals has made it onto these pages several times over the years,
not least as a LoRA gateway
. | 5 | 4 | [
{
"comment_id": "8110654",
"author": "D",
"timestamp": "2025-03-19T20:35:14",
"content": "As for why momentum (and gravity) makes this less trivial: it gives you options of how to get the ball out of a depression. For example you could rock the device back and forth, helping the ball climb a little ... | 1,760,371,601.227539 | ||
https://hackaday.com/2025/03/19/floss-weekly-episode-825-open-source-ci-with-semaphore/ | FLOSS Weekly Episode 825: Open Source CI With Semaphore | Jonathan Bennett | [
"Hackaday Columns",
"Podcasts"
] | [
"ci/cd",
"FLOSS Weekly",
"semaphore"
] | This week,
Jonathan Bennett
and Ben Meadors talk to
Darko Fabijan
about Semaphore, the newly Open Sourced Continuous Integration solution! Why go Open, and how has it gone so far? Watch to find out!
Semaphore Uncut Podcast:
https://semaphore.io/podcast
Discord:
https://discord.gg/FBuUrV24NH
https://www.youtube.com/c/SemaphoreCI
Semaphore blog:
https://semaphoreci.com/blog
Semaphore on X:
https://x.com/semaphoreci
Did you know you can watch the live recording of the show right on
our YouTube Channel
? Have someone you’d like us to interview? Let us know, or contact the guest and have them contact us!
Take a look at the schedule here
.
Direct Download
in DRM-free MP3.
If you’d rather read along,
here’s the transcript for this week’s episode
.
Places to follow the FLOSS Weekly Podcast:
Spotify
RSS
Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)
Licensed under
Creative Commons: By Attribution 4.0 License | 0 | 0 | [] | 1,760,371,601.313942 | ||
https://hackaday.com/2025/03/19/from-the-ashes-coal-ash-may-offer-rich-source-of-rare-earth-elements/ | From The Ashes: Coal Ash May Offer Rich Source Of Rare Earth Elements | Dan Maloney | [
"Hackaday Columns",
"News"
] | [
"ash",
"coal",
"rare-earth",
"REEYSc",
"scandium",
"yttrium"
] | For most of history, the world got along fine without the rare earth elements. We knew they existed, we knew they weren’t really all that rare, and we really didn’t have much use for them — until we discovered just how useful they are and made ourselves absolutely dependent on them, to the point where not having them would literally grind the world to a halt.
This dependency has spurred a search for caches of rare earth elements in the strangest of places, from muddy sediments on the sea floor to asteroids. But there’s one potential source that’s much closer to home:
coal ash waste
. According to
a study
from the University of Texas Austin, the 5 gigatonnes of coal ash produced in the United States between 1950 and 2021 might contain as much as $8.4 billion worth of REEYSc — that’s the 16 lanthanide rare earth elements plus yttrium and scandium, transition metals that aren’t strictly rare earths but are geologically associated with them and useful in many of the same ways.
The study finds that about 70% of this coal ash largesse could still be accessible in the landfills and ponds in which it was dumped after being used for electrical generation or other industrial processes; the remainder is locked away in materials like asphalt and concrete, where it was used as a filler. The concentration of REEYSc in ash waste depends on where the coal was mined and ranges from 264 mg/kg for Powder River coal to 431 mg/kg for coal from the Appalachian Basin. Oddly, they find that recovery rates are inversely proportional to the richness of the ash.
The study doesn’t discuss any specific methods for recovery of REEYSc from coal ash at the industrial scale, but it does reference
an earlier paper
that mentions possible methods we’ve seen before in our
Mining and Refining
series, including physical beneficiation, which separates the desired minerals from the waste material using properties such as shape, size, or density, and hydrometallurgical methods such as acid leaching or ion exchange. The paper also doesn’t mention how these elements accumulated in the coal ash in the first place, although we assume that Carboniferous-period plants bioaccumulated the minerals before they died and started turning into coal.
Of course, this is just preliminary research, and no attempt has yet been made to commercialize rare earth extraction from coal ash. There are probably serious technical and regulatory hurdles, not least of which would be valid concerns for the environmental impacts of disturbing long-ignored ash piles. On the other hand, the study mentions “mine-mouth” power plants, where mines and generating plants were colocated as possibly the ideal place to exploit since ash was used to backfill the mine works right on the same site. | 39 | 11 | [
{
"comment_id": "8110609",
"author": "BobH",
"timestamp": "2025-03-19T17:13:08",
"content": "If there is that much in the ash, I wonder how much is in the unburned coal?",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8110629",
"author": "paulvdh\\",
... | 1,760,371,601.386082 | ||
https://hackaday.com/2025/03/19/reviving-a-maplin-4600-diy-synthesizer-from-the-1970s/ | Reviving A Maplin 4600 DIY Synthesizer From The 1970s | Donald Papp | [
"classic hacks",
"Musical Hacks"
] | [
"diy",
"maplin 4600",
"refurbished",
"synth",
"synthesizer",
"vintage"
] | A piece of musical history is the Maplin 4600, a DIY electronic music synthesizer from the 1970s. The design was published in an Australian electronics magazine and sold as a DIY kit, and [LOOK MUM NO COMPUTER] got his hands on
an original Maplin 4600 that he refurbishes and puts through its paces
.
Inserting conductive pegs is how the operator connects different inputs and outputs.
The Maplin 4600 is a (mostly) analog device with a slightly intimidating-looking layout. It features multiple oscillators, mixers, envelope generators, filters, and a complex-looking patch bay on the right hand side that is reminiscent of a breadboard. By inserting conductive pins, one can make connections between various inputs and outputs.
Internally the different features and circuits are mostly unconnected from one another by default, so the patch board is how the instrument is “programmed” and the connections made can be quite complex. The 4600 is one of a few synthesizer designs by [Trevor Marshall], who has some additional details about
on his website
.
The video (embedded below) is a complete walk-through of the unit, including its history, quirks, and design features. If you’d like to skip directly to a hands-on demonstrating how it works, that begins around
the 10:15 mark
.
Synthesizers have a rich DIY history and it’s fascinating to see an in-depth look at this one. And hey, if you like your synths complex and intimidating, do yourself a favor and
check out the
Starship One
. | 16 | 7 | [
{
"comment_id": "8110578",
"author": "alialiali",
"timestamp": "2025-03-19T15:59:49",
"content": "Surely not Maplin as in the ill fated UK hobbist electronics chain?",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8110583",
"author": "David H",
... | 1,760,371,601.440939 | ||
https://hackaday.com/2025/03/19/so-what-is-a-supercomputer-anyway/ | So What Is A Supercomputer Anyway? | Maya Posch | [
"computer hacks",
"Featured",
"History",
"Slider"
] | [
"eniac",
"illiac",
"parallel computing",
"supercomputer"
] | Over the decades there have been many denominations coined to classify computer systems, usually when they got used in different fields or technological improvements caused significant shifts. While the very first electronic computers were very limited and often not programmable, they would soon morph into something that we’d recognize today as a computer, starting with World War 2’s Colossus and ENIAC, which saw use with cryptanalysis and military weapons programs, respectively.
The first commercial digital electronic computer wouldn’t appear until 1951, however, in the form of the
Ferranti Mark 1
. These 4.5 ton systems mostly found their way to universities and kin, where they’d find welcome use in engineering, architecture and scientific calculations. This became the focus of new computer systems, effectively the equivalent of a scientific calculator. Until the invention of the transistor, the idea of a computer being anything but a hulking, room-sized monstrosity was preposterous.
A few decades later, more computer power could be crammed into less space than ever before including ever higher density storage. Computers were even found in toys, and amidst a whirlwind of mini-, micro-, super-, home-, minisuper- and mainframe computer systems, one could be excused for asking the question: what even is a supercomputer?
Today’s Supercomputers
ORNL’s Summit supercomputer, fastest until 2020 (Credit: ORNL)
Perhaps a fair way to classify supercomputers is that the ‘supercomputer’ aspect is a highly
time-limited property
. During the 1940s, Colossus and ENIAC were without question the supercomputers of their era, while 1976’s Cray-1 wiped the floor with everything that came before, yet all of these are archaic curiosities next to today’s top two supercomputers. Both the
El Capitan
and Frontier supercomputers are exascale level machines — they carry out exaFLOPS in double precision IEEE 754 calculations — based around commodity x86_64 CPUs in a massively parallel configuration.
Taking up 700 m
2
of floor space at the Lawrence Livermore National Laboratory (LLNL) and drawing 30 MW of power, El Capitan’s 43,808 AMD EPYC CPUs are paired with the same number of
AMD Instinct MI300A
accelerators, each containing 24 Zen 4 cores plus CDNA3 GPU and 128 GB of HBM3 RAM. Unlike the monolithic ENIAC, El Capitan’s 11,136 nodes, containing four MI300As each, rely on a number of high-speed interconnects to distribute computing work across all cores.
At LLNL, El Capitan is used for effectively the same top secret government things as ENIAC was, while Frontier at Oak Ridge National Laboratory (ORNL) was the fastest supercomputer before El Capitan came online about three years later. Although currently LLNL and ORNL have the fastest supercomputers, there are many more of these systems in use around the world, even for innocent scientific research.
Looking at the current list of supercomputers, such as
today’s Top 9
, it’s clear that not only can supercomputers perform a lot more operations per second, they also are invariably massively parallel computing clusters. This wasn’t a change that was made easily, as parallel computing comes with a whole stack of complications and problems.
The Parallel Computing Shift
ILLIAC IV massively parallel computer’s Control Unit (CU). (Credit: Steve Jurvetson,
Wikimedia
)
The first massively parallel computer was the
ILLIAC IV
, conceptualized by Daniel Slotnick in 1952 and first successfully put into operation in 1975 when it was connected to ARPANET. Although only one quadrant was fully constructed, it produced 50 MFLOPS compared to the Cray-1’s 160 MFLOPS a year later. Despite the immense construction costs and spotty operational history, it provided a most useful testbed for developing parallel computation methods and algorithms until the system was decommissioned in 1981.
There was a lot of pushback against the idea of massively parallel computation, however, with Seymour Cray famously comparing the idea of using many parallel vector processors instead of a single large one akin to ‘plowing a field with 1024 chickens instead of two oxen’.
Ultimately there is only so far you can scale a singular vector processor, of course, while parallel computing promised much better scaling, as well as the use of commodity hardware. A good example of this is a so-called
Beowulf cluster
, named after the original 1994 parallel computer built by Thomas Sterling and Donald Becker at NASA. This can use plain desktop computers, wired together using for example Ethernet and with open source libraries like Open MPI enabling massively parallel computing without a lot of effort.
Not only does this approach enable the assembly of a ‘supercomputer’ using cheap-ish, off-the-shelf components, it’s also effectively the approach used for LLNL’s El Capitan, just with not very cheap hardware, and not very cheap interconnect hardware, but still cheaper than if one were to try to build a monolithic vector processor with the same raw processing power after taking the messaging overhead of a cluster into account.
Mini And Maxi
David Lovett of Usagi Electri sitting among his FPS minisupercomputer hardware. (Credit: David Lovett, YouTube)
One way to look at supercomputers is that it’s not about the scale, but what you do with it. Much like how government, large businesses and universities would end up with ‘Big Iron’ in the form of mainframes and supercomputers, there was a big market for
minicomputers
too. (At this time ‘mini’ meant something like a PDP-11 that’d comfortably fit in the corner of an average room at an office or university.)
The high-end versions of minicomputers were called ‘
superminicomputer
‘, which is not to be confused with
minisupercomputer
, which is another class entirely. During the 1980s there was a brief surge in this latter class of supercomputers that were designed to bring solid vector computing and similar supercomputer feats down to a size and price tag that might entice departments and other customers who’d otherwise not even begin to consider such an investment.
The manufacturers of these ‘budget-sized supercomputers’ were generally not the typical big computer manufacturers, but instead smaller companies and start-ups like
Floating Point Systems
(later acquired by Cray) who sold array processors and similar parallel, vector computing hardware.
Recently David Lovett (AKA Mr. Usagi Electric)
embarked on a quest
to recover and reverse-engineer as much FPS hardware as possible, with one of the goals being to build a full minisupercomputer system as companies and universities might have used them in the 1980s. This would involve attaching such an array processor to a PDP-11/44 system.
Speed Versus Reliability
Amidst all of these definitions, the distinction between a mainframe and a supercomputer is much easier and more straightforward at least. A
mainframe
is a computer system that’s designed for bulk data processing with as much built-in reliability and redundancy as the price tag allows for. A modern example is
IBM’s Z-series
of mainframes, with the ‘Z’ standing for ‘zero downtime’. These kind of systems are used by financial institutions and anywhere else where downtime is counted in millions of dollars going up in (literal) flames every second.
This means hot-swappable processor modules, hot-swappable and redundant power supplies, not to mention hot spares and a strong focus on fault tolerant computing. All of these features are less relevant for a supercomputer, where raw performance is the defining factor when running days-long simulations and when other ways to detect flaws exist without requiring hardware-level redundancy.
Considering the brief lifespan of supercomputers, currently in the order of a few years, compared to decades with mainframes and the many years that the microcomputers which we have on our desks can last, the life of a supercomputer seems like that of a bright and very brief flame, indeed.
Top image: Marlyn Wescoff and Betty Jean Jennings configuring plugboards on the ENIAC computer (Source:
US National Archives
) | 33 | 14 | [
{
"comment_id": "8110574",
"author": "Antron Argaiv",
"timestamp": "2025-03-19T15:53:12",
"content": "I heard Lily Tomlin’s voice as Ernestine when I saw that first photo. “A gracious good morning…”",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8110581",
... | 1,760,371,601.57822 | ||
https://hackaday.com/2025/03/19/make-fancy-resin-printer-3d-models-fdm-friendly/ | Make Fancy Resin Printer 3D Models FDM-Friendly | Donald Papp | [
"3d Printer hacks",
"Software Hacks"
] | [
"3d model",
"3d printing",
"blender",
"FDM",
"resin",
"thick supports"
] | Do you like high-detail 3D models intended for resin printing, but wish you could more easily print them on a filament-based FDM printer? Good news, because
[Jacob] of
Painted4Combat
shared a tool he created
to make 3D models meant for resin printers — the kind popular with tabletop gamers — easier to port to FDM. It comes in the form of a Blender add-on called
Resin2FDM.
Intrigued, but wary of your own lack of experience with Blender? No problem, because he also
made a video that walks you through the whole thing step-by-step
.
Resin2FDM separates the model from the support structure, then converts the support structure to be FDM-friendly.
3D models intended for resin printing aren’t actually any different, format-wise, from models intended for FDM printers. The differences all come down to the features of the model and how well the printer can execute them.
Resin printing is very different from FDM
, so printing a model on the “wrong” type of printer will often have disappointing results. Let’s look at why that is, to better understand what makes [Jacob]’s tool so useful.
Rafts and a forest of thin tree-like supports are common in resin printing. In the tabletop gaming scene, many models come pre-supported for convenience. A fair bit of work goes into optimizing the orientation of everything for best printed results, but the benefits don’t carry directly over to FDM.
For one thing, supports for resin prints are usually too small for an FDM printer to properly execute — they tend to be very thin and very tall, which is probably the least favorable shape for FDM printing. In addition, contact points where each support tapers down to a small point that connects to the model are especially troublesome; FDM slicer software will often simply consider those features too small to bother trying to print. Supports that work on a resin printer tend to be too small or too weak to be effective on FDM, even with a 0.2 mm nozzle.
To solve this, [Jacob]’s tool allows one to separate the model itself from the support structure. Once that is done, the tool further allows one to tweak the nest of supports, thickening them up
just enough
to successfully print on an FDM printer, while leaving the main model unchanged. The result is a support structure that prints well via FDM, allowing the model itself to come out nicely, with a minimum of alterations to the original.
Resin2FDM
is available in two versions, the Lite version is free and an advanced version with more features is available to [Jacob]’s Patreon subscribers. The video (embedded below) covers everything from installation to use, and includes some general tips for best results. Check it out if you’re interested in how [Jacob] solved this problem, and keep it in mind for the next time you run across a pre-supported model intended for resin printing that you wish you could print with FDM. | 17 | 6 | [
{
"comment_id": "8110525",
"author": "RunnerPack",
"timestamp": "2025-03-19T13:27:53",
"content": "If you can split the supports and the model, why not just delete the supports entirely and let the (FDM) slicer put them where it deems best?",
"parent_id": null,
"depth": 1,
"replies": [
... | 1,760,371,601.740613 | ||
https://hackaday.com/2025/03/20/laser-harp-sets-the-tone/ | Laser Harp Sets The Tone | Bryan Cockfield | [
"Laser Hacks"
] | [
"arduino",
"high power",
"laser",
"laser harp",
"microcontroller",
"midi",
"music",
"persistence of vision"
] | In many ways, living here in the future is quite exiting. We have access to the world’s information instantaneously and can get plenty of exciting tools and hardware delivered to our homes in ways that people in the past with only a Sears catalog could only dream of. Lasers are of course among the exciting hardware available, which can be purchased with extremely high power levels. Provided the proper safety precautions are taken,
that can lead to some interesting builds like this laser harp which uses a 3W laser for its strings
.
[Cybercraftics]’ musical instrument is using a single laser to generate seven harp strings, using a fast stepper motor to rotate a mirror to precise locations, generating the effect via persistence of vision. Although he originally planned to use one Arduino for this project, the precise timing needed to keep the strings in the right place was getting corrupted by adding MIDI and the other musical parts to the project, so he split those out to a second Arduino.
Although his first prototype worked, he did have to experiment with the sensors used to detect his hand position on the instrument quite a bit before getting good results. This is where the higher power laser came into play, as the lower-powered ones weren’t quite bright enough. He also uses a pair of white gloves which help illuminate a blocked laser. With most of the issues ironed out, [Cybercraftics] notes that there’s room for improvement but still has a working instrument that seems like a blast to play. If you’re still stuck in the past without easy access to lasers, though,
it’s worth noting that there are plenty of other ways to build futuristic instruments as well
. | 16 | 10 | [
{
"comment_id": "8110942",
"author": "lightislight",
"timestamp": "2025-03-20T21:09:00",
"content": "I am surprised they still have their eye sight… 3W laser aimed directly towards their face and they are looking for the beam with their hands. One wrist watch reflection or sprinkler on the ceiling a... | 1,760,371,601.685677 | ||
https://hackaday.com/2025/03/20/three-spi-busses-are-one-too-many-on-this-cheap-yellow-display/ | Three SPI Busses Are One Too Many On This Cheap Yellow Display | Jenny List | [
"Microcontrollers"
] | [
"Cheap Yellow Display",
"ESP32",
"spi"
] | The Cheap Yellow Display may not be the fastest of ESP32 boards with its older model chip and 4 MB of memory, but its low price and useful array of on-board peripherals has made it something of a hit in our community. Getting the most out of the hardware still presents some pitfalls though, as [Mark Stevens] found out when using one for an environmental data logger. The problem was that display, touch sensor, and SD card had different SPI busses, of which the software would only recognise two.
His solution involves a simple hardware mod
, which may benefit many others doing similar work.
It’s simple enough, put the LCD and SD card on the same bus, retaining their individual chip select lines. There’s a track to be cut and a bit of wiring to be done, but nothing that should tax most readers too much. We’re pleased to see more work being done with this board, as it remains a promising platform, and any further advancements for it are a good thing. If you’re interested in giving it a go, then
we’ve got some inspiration for you
. | 25 | 10 | [
{
"comment_id": "8110880",
"author": "Ben",
"timestamp": "2025-03-20T15:48:53",
"content": "Awful. What is the benefit over a software solution?",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8111302",
"author": "Dia Rear",
"timestamp": "2025... | 1,760,371,601.639506 | ||
https://hackaday.com/2025/03/20/linux-fu-a-warp-speed-prompt/ | Linux Fu: A Warp Speed Prompt | Al Williams | [
"Hackaday Columns",
"Linux Hacks"
] | [
"bash",
"linux",
"prompt",
"zsh"
] | If you spend a lot of time at the command line, you probably have either a very basic prompt or a complex, information-dense prompt. If you are in the former camp, or you just want to improve your shell prompt, have a look at
Starship
. It works on the most common shells on most operating systems, so you can use it everywhere you go, within reason. It has the advantage of being fast and you can also customize it all that you want.
What Does It Look Like?
It is hard to explain exactly what the Starship prompt looks like. First, you can customize it almost infinitely, so there’s that. Second, it adapts depending on where you are. So, for example, in a git-controlled directory, you get info about the git status unless you’ve turned that off. If you are in an ssh session, you’ll see different info than if you are logged in locally.
However, here’s a little animation from their site that will give you an idea of what you might expect:
https://hackaday.com/wp-content/uploads/2025/03/demo.webm
Installation
The web site says you need a
Nerd Font
in your terminal. I didn’t remember doing that on purpose, but apparently I had one already.
Next, you just have to install using one of the methods they provide, which depends on your operating system. For Linux, you can run the installer:
curl -sS https://starship.rs/install.sh | sh
Sure, you should download it first and look to make sure it won’t reformat your hard drive or something, but it was fine when we did it.
Finally, you have to run an init command. How you do that depends on your shell and they have plenty of examples. There’s even a way to use it with cmd.exe on Windows!
Customization
The default isn’t bad but, of course, you are going to want to change things. Oddly, the system doesn’t create a default configuration file. It just behaves a certain way if it doesn’t find one. You must make your own ~/.config/starship.toml file. You can change where the file lives using an environment variable, if you prefer, but you still have to create it.
The TOML file format has sections like an INI file. Just be aware that any global options have to come before any section (that is, there’s no [global] tag). If you put things towards the bottom of the file, they won’t seem to work and it is because they have become part of the last tag.
There are a number of modules and each module reads data from a different section. For example, on my desktop I have no need for battery status so:
[battery]
disabled = true
Strings
In the TOML file you can use single or double quotes. You can also triple a quote to make a string break lines (but the line breaks are not part of the string). The single quotes are treated as a literal, while double quotes require escape characters for special things.
You can use variables in strings like $version or $git_branch. You can also place part of a string in brackets and then formating for the string in parenthesis immediately following. For example:
'[off](fg:red bold)'
Finally, you can have a variable print only if it exists:
'(#$id)'
If $id is empty, this does nothing. Otherwise, it will print the # and the value.
Globals and Modules
You can find all the configuration options — and there are many — in the
Starship documentation
. Of primary interest is the global format variable. This sets each module that is available. However, you can also use $all to get all the otherwise unspecified modules. By default, the format variable starts with $username $hostname. Suppose you wanted it to be different. You could write:
format='$hostname ! $username $all'
You’ll find many modules that show the programming language used for this directory, version numbers, and cloud information. You can shut things off, change formatting, or rearrange. Some
user-submitted customizations
are available, too. Can’t find a module to do what you want? No problem.
Super Custom
I wanted to show the status of my watercooler, so I created a custom section in the TOML file:
[custom.temp]
command = 'temp-status|grep temp|cut -d " " -f 7'
when = true
format='$output°'
The command output winds up in, obviously, $output. In this case, I always want the module to output and the format entry prints the output with a degree symbol after it. Easy!
Of Course, There are Always Others
There are other prompt helpers out there, especially if you use zsh (e.g.,
Oh My Zsh
). However, if you aren’t on zsh, your options are more limited.
Oh My Posh
is another cross-shell entry into the field. Of course, you don’t absolutely need any of these. They work because shells give you variables like PS1 and PROMPT_COMMAND, so you can always roll your own to be as simple or complex as you like. People have been doing their own
for a very long time
.
If you want to do your own for bash, you can get some
help online
. Or, you could
add help to bash
, too. | 27 | 8 | [
{
"comment_id": "8110839",
"author": "steelman",
"timestamp": "2025-03-20T14:10:22",
"content": "<blockquote>curl -sShttps://starship.rs/install.sh| sh<blockquote>Never, ever do this. No.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8110853",
"auth... | 1,760,371,602.065956 | ||
https://hackaday.com/2025/03/20/chemistry-meets-mechatronics-in-this-engaging-art-piece/ | Chemistry Meets Mechatronics In This Engaging Art Piece | Dan Maloney | [
"Art"
] | [
"anthocyanin",
"cabbage",
"electrooxidation",
"electroreduction",
"gantry",
"peristaltic",
"pigment"
] | There’s a classic grade school science experiment that involves extracting juice from red cabbage leaves and using it as a pH indicator. It relies on anthocyanins, pigmented compounds that give the cabbage its vibrant color but can change depending on the acidity of the environment they’re in, from pink in acidic conditions to green at higher pH. And anthocyanins are exactly what power
this unusual kinetic art piece
.
Even before it goes into action, [Nathalie Gebert]’s
Anthofluid
is pretty cool to look at. The “canvas” of the piece is a thin chamber formed by plexiglass sheets, one of which is perforated by an array of electrodes. A quartet of peristaltic pumps fills the chamber with a solution of red cabbage juice from a large reservoir, itself a mesmerizing process as the purple fluid meanders between the walls of the chamber and snakes around and between the electrodes. Once the chamber is full, an X-Y gantry behind the rear wall moves to a random set of electrodes, deploying a pair of conductors to complete the circuit. When a current is applied, tendrils of green and red appear, not by a pH change but rather by the oxidation and reduction reactions occurring at the positive and negative electrodes. The colors gently waft up through the pale purple solution before fading away into nothingness. Check out the video below for the very cool results.
We find
Anthofluid
terribly creative, especially in the use of such an unusual medium as red cabbage juice. We also appreciate the collision of chemistry, electricity, and mechatronics to make a piece of art that’s so kinetic but also so relaxing at the same time. It’s the same feeling that
[Nathalie]’s previous art piece
gave us as it created images on screens of moving thread. | 6 | 5 | [
{
"comment_id": "8110868",
"author": "Code",
"timestamp": "2025-03-20T15:33:52",
"content": "Someone should make a clock out of that*I should make a clock out of that*I already have too many projects*Someone should make a clock out of that",
"parent_id": null,
"depth": 1,
"replies": []
... | 1,760,371,601.933605 | ||
https://hackaday.com/2025/03/20/pieeg-kit-is-a-self-contained-biosignal-laboratory/ | PiEEG Kit Is A Self-Contained Biosignal Laboratory | Tom Nardi | [
"Raspberry Pi"
] | [
"biosignals",
"eeg",
"electroencephalogram",
"PiEEG"
] | Back in 2023, we first brought you word of the PiEEG: a low-cost Raspberry Pi based device designed for detecting and analyzing electroencephalogram (EEG) and other biosignals for the purposes of experimenting with brain-computer interfaces. Developed by [Ildar Rakhmatulin], the hardware has gone through several revisions since then,
with this latest incarnation
promising to be the most versatile and complete take on the concept yet.
At the core of the project is the PiEEG board itself, which attaches to the Raspberry Pi and allows the single-board computer (SBC) to interface with the necessary electrodes. For safety, the PiEEG and Pi need to remain electrically isolated, so they would have to be powered by a battery. This is no problem while capturing data, as the Pi has enough power to process the incoming signals using the included Python tools, but could be an issue if you wanted to connect the PiEEG system to another computer, say.
For the new PiEEG Kit, the hardware is now enclosed in its own ABS carrying case, which includes an LCD right in the lid. While you’ve still got to provide your own power (such as a USB battery bank), having the on-board display removes the need to connect the Pi to some other system to visualize the data. There’s also a new PCB that allows the connection of additional environmental sensors, breakouts for I2C, SPI, and GPIO, three buttons for user interaction, and an interface for connecting the electrodes that indicates where they should be placed on the body right on the silkscreen.
The
crowdsourcing campaign for the PiEEG Kit
is set to begin shortly, and
the earlier PiEEG-16 hardware
is available for purchase currently if you don’t need the fancy new features. Given the fact that the
original PiEEG was funded beyond 500% during its campaign in 2023
, we imagine there’s going to be plenty of interest in the latest-and-greatest version of this fascinating project. | 9 | 5 | [
{
"comment_id": "8110784",
"author": "Nk",
"timestamp": "2025-03-20T09:28:43",
"content": "Can you use this to make a BCI?Are there libraries or software to do that?",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8110832",
"author": "Ron",
"t... | 1,760,371,602.123944 | ||
https://hackaday.com/2025/03/19/worlds-smallest-blinky-now-even-smaller/ | World’s Smallest Blinky, Now Even Smaller | Dan Maloney | [
"Microcontrollers"
] | [
"ATtiny20",
"blinky",
"led",
"microcontroller",
"microsoldering",
"tantalum"
] | Here at Hackaday, it’s a pretty safe bet that putting “World’s smallest” in the title of an article will instantly attract comments claiming that someone else built a far smaller version of the same thing. But that’s OK, because if there’s something smaller than
this nearly microscopic LED blinky build
, we definitely want to know about it.
The reason behind [Mike Roller]’s build is simple: he wanted to build something smaller than
the previous smallest blinky
. The 3.2-mm x 2.5-mm footprint of that effort is a tough act to follow, but technology has advanced somewhat in the last seven years, and [Mike] took advantage of that by basing his design on an ATtiny20 microcontroller in a WLCSP package and an 0201 LED, along with a current-limiting resistor and a decoupling capacitor. Powering the project is a 220-μF tantalum capacitor, which at a relatively whopping 3.2 mm x 1.6 mm determines the size of the PCB, which [Mike] insisted on using.
Assembling the project was challenging, to say the least. [Mike] originally tried a laboratory hot plate to reflow the board, but when the magnetic stirrer played havoc with the parts, he switched to a hot-air rework station with a very low airflow. Programming the microcontroller almost seemed like it was more of a challenge; when the pogo pins he was planning to use proved too large for the job he tacked leads made from 38-gauge magnet wire to the board with the aid of a micro hot air tool.
After building version one, [Mike] realized that even smaller components were available, so there’s now a 2.4 mm x 1.5 mm version using an 01005 LED. We suspect there’ll be a version 3.0 soon, though — he mentions that
the new TI ultra-small microcontrollers
weren’t available yet when he pulled this off, and no doubt he’ll want to take a stab at this again. | 29 | 12 | [
{
"comment_id": "8110749",
"author": "macsimski",
"timestamp": "2025-03-20T06:56:28",
"content": "nothing to sneeze at.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8110757",
"author": "udif",
"timestamp": "2025-03-20T08:01:24",
"co... | 1,760,371,602.001362 | ||
https://hackaday.com/2025/03/19/pick-up-a-pebble-again/ | Pick Up A Pebble Again | Jenny List | [
"Wearable Hacks"
] | [
"pebble",
"smartwatch",
"wearable"
] | A decade ago, smartwatches were an unexplored avenue full of exotic promise. There were bleeding-edge and eye-wateringly expensive platforms from the likes of Samsung or Apple, but for the more experimental among technophiles there was the Pebble. Based on a microcontroller and with a relatively low-resolution display, it was the subject of a successful crowdfunding campaign and became quite the thing to have. Now long gone, it has survived in open-source form, and now if you’re a Pebble die-hard
you can even buy a new Pebble
. We’re not sure about their choice of name though, we think calling something the “Core 2 Duo” might attract the attention of Intel’s lawyers.
The idea is broadly the same as the original, and remains compatible with software from back in the day. New are some extra sensors, longer battery life, and an nRF52840 BLE microcontroller running the show. It certainly captures the original well, however we’re left wondering whether a 2013 experience still cuts it in 2025 at that price. We suspect in that vein it would be the ideal compliment to your game controller when playing
Grand Theft Auto V
, another evergreen 2013 hit.
We look forward to seeing where this goes, and
we reported on the OS becoming open source earlier this year
. Perhaps someone might produce a piece of open source hardware to do the same job? | 38 | 16 | [
{
"comment_id": "8110728",
"author": "alt",
"timestamp": "2025-03-20T04:13:48",
"content": "maybe its just me but it doesnt seem that expensive considering how much most “smartwatches” cost and can’t even last more than a day or two without needing to be charged",
"parent_id": null,
"depth":... | 1,760,371,602.290058 | ||
https://hackaday.com/2025/03/19/glasses-that-transcribe-text-to-audio/ | “Glasses” That Transcribe Text To Audio | Lewin Day | [
"Raspberry Pi",
"Wearable Hacks"
] | [
"glasses",
"optical character recognition",
"speech synthesis",
"text to speech"
] | Glasses for the blind might sound like an odd idea, given the traditional purpose of glasses and the issue of vision impairment. However, eighth-grade student [Akhil Nagori] built these glasses with an alternate purpose in mind. They’re not really for seeing. Instead,
they’re outfitted with hardware to capture text and read it aloud.
Yes, we’re talking about real-time text-to-audio transcription, built into a head-worn format. The hardware is pretty straightforward: a Raspberry Pi Zero 2W runs off a battery and is outfitted with the usual first-party camera. The camera is mounted on a set of eyeglass frames so that it points at whatever the wearer might be “looking” at. At the push of a button, the camera captures an image, and then passes it to an API which does the optical character recognition. The text can then be passed to a speech synthesizer so it can be read aloud to the wearer.
It’s funny to think about how advanced this project really is. Jump back to the dawn of the microcomputer era, and such a device would have been a total flight of fancy—something a researcher might make a PhD and career out of. Indeed,
OCR
and
speech synthesis
alone were challenge enough. Today, you can stand on the shoulders of giants and include such mighty capability in a homebrewed device that cost less than $50 to assemble. It’s a neat project, too, and one that we’re sure taught [Akhil] many valuable skills along the way. | 11 | 9 | [
{
"comment_id": "8110455",
"author": "shinsukke",
"timestamp": "2025-03-19T08:39:33",
"content": "Very cool project, and by an eighth grader no less!I am really out of touch with machine vision libraries etc. In my mind, they are still hard to use and out of reach, and OCR is unobtainable by an indi... | 1,760,371,602.336925 | ||
https://hackaday.com/2025/03/18/spy-tech-build-your-own-laser-eavesdropper/ | Spy Tech: Build Your Own Laser Eavesdropper | Heidi Ulrich | [
"Laser Hacks",
"Security Hacks"
] | [
"laser",
"microphone",
"noise",
"sensor",
"spy",
"spy tech",
"surveillance"
] | Laser microphones have been around since the Cold War. Back in those days, they were a favorite tool of the KGB – allowing spies to listen in on what was being said in a room from a safe distance.
This project by [SomethingAbtScience]
resurrects that concept with a DIY build that any hacker worth their soldering iron can whip up on a modest budget. And let’s face it,
few things are cooler
than turning a distant window into a microphone.
At its core this hack shines a laser on a window, detects the reflected light, and picks up subtle vibrations caused by conversations inside the room. [SomethingAbtScience] uses an ordinary red laser (visible, because YouTube rules) and repurposes an amplifier circuit ripped from an old mic, swapping the capsule for a photodiode. The build is elegant in its simplicity, but what really makes it shine is the attention to detail: adding a polarizing filter to cut ambient noise and 3D printing a stabilized sensor mount. The output is still a bit noisy, but with some fine tuning – and perhaps a second sensor for differential analysis – there’s potential for crystal-clear audio reconstruction. Just don’t expect it to pass MI6 quality control.
While you probably won’t be spying on diplomats anytime soon, this project is a fascinating glimpse into a bygone era of
physical surveillance
. It’s also a reminder of how much can be accomplished with a laser pointer, some ingenuity, and the curiosity to see how far a signal can travel. | 35 | 11 | [
{
"comment_id": "8110441",
"author": "Hugh",
"timestamp": "2025-03-19T08:02:01",
"content": "Interresting hackThe background noise looks like white noise or so.It could be coming from the sensor itself or from the preamplifier.According to the documents, it appears that the Russians used the infrare... | 1,760,371,602.408559 | ||
https://hackaday.com/2025/03/18/speeding-up-your-projects-with-direct-memory-access/ | Speeding Up Your Projects With Direct Memory Access | Lewin Day | [
"Microcontrollers"
] | [
"code",
"Direct Memory Access",
"dma",
"embedded"
] | Here’s the thing about coding. When you’re working on embedded projects, it’s quite easy to run into hardware limitations, and quite suddenly, too. You find yourself desperately trying to find a way to speed things up, only… there are no clock cycles to spare. It’s at this point that you might reach for the magic of direct memory access (DMA).
[Larry] is here to advocate for its use.
DMA isn’t just for the embedded world; it was once a big deal on computers, too. It’s just rarer these days due to security concerns and all that. Whichever platform you’re on, though, it’s a valuable tool to have in your arsenal. As [Larry] explains, DMA is a great way to move data from memory location to memory location, or from memory to peripherals and back, without involving the CPU. Basically, a special subsystem handles trucking data from A to B while the CPU gets on with whatever other calculations it had to do. It’s often a little more complicated in practice, but that’s what [Larry] takes pleasure in explaining.
Indeed, back before I was a Hackaday writer, I was no stranger to DMA techniques myself—
and I got my project published here!
I put it to good use in speeding up an LCD library for the Arduino Due. It was the perfect application for DMA—my main code could handle updating the graphics buffer as needed, while the DMA subsystem handled trucking the buffer out to the LCD quicksmart.
If you’re struggling with updating a screen or LED strings, or you need to do something fancy with sound, DMA might just be the ticket. Meanwhile, if you’ve got your own speedy DMA tricks up your sleeve,
don’t hesitate to let us know! | 37 | 9 | [
{
"comment_id": "8110370",
"author": "David H",
"timestamp": "2025-03-19T02:06:28",
"content": "Ex-Amiga coder here. DMA, you say? That brings back some memories. Can we talk about the copper and the blitter, too? As you allude, the words “DMA” and “security” don’t co-exist entirely happily, but the... | 1,760,371,602.608233 | ||
https://hackaday.com/2025/03/18/ultra-low-power-soil-moisture-sensor/ | Ultra-Low Power Soil Moisture Sensor | Bryan Cockfield | [
"green hacks"
] | [
"capacitance",
"capacitive",
"houseplant",
"moisture",
"plant",
"sensor",
"soil",
"stm32",
"water"
] | Electricity can be a pretty handy tool when it stays within the bounds of its wiring. It’s largely responsible for our modern world and its applications are endless. When it’s not running in wires or electronics though, things can get much more complicated even for things that seem simple on the surface. For example, measuring moisture in soil seems straightforward, but corrosion presents immediate problems. To combat the problems with measuring things in the natural world with electricity,
[David] built this capacitive soil moisture sensor
which also has the benefit of using an extremely small amount of energy to operate.
The sensor is based on an STM32 microcontroller, in this case one specifically optimized for low-power applications. The other low-power key to this build is the small seven-segment e-ink display. The segments are oriented as horizontal lines, making this a great indicator for measuring a varying gradient of any type. The microcontroller only wakes up every 15 minutes, takes a measurement, and then updates the display before going back to sleep.
To solve the problem resistive moisture sensors have where they’re directly in contact with damp conditions and rapidly corrode, [David] is using a capacitive sensor instead which measures a changing capacitance as moisture changes. This allows the contacts to be much more isolated from the environment. The sensor has been up and running for a few months now with the coin cell driving the system still going strong and the house plants still alive and properly watered. Of course if you’re looking to take your houseplant game to the next level
you could always build a hydroponics system
which automates not only the watering of plants but everything else as well. | 13 | 6 | [
{
"comment_id": "8110332",
"author": "shinsukke",
"timestamp": "2025-03-18T23:28:50",
"content": "Ynvisible displays are more similar to segment LCDs, than e-ink/epaper displays. Driving them is similar, you generate a voltage across them and the segments change their contrast. Ynvisible segments ne... | 1,760,371,602.530036 | ||
https://hackaday.com/2025/03/18/a-foot-pedal-to-supplement-your-keyboard/ | A Foot Pedal To Supplement Your Keyboard | Lewin Day | [
"Peripherals Hacks"
] | [
"ctrl",
"foot pedal",
"foot pedals",
"keyboard"
] | It’s 2025, and you’re still probably pressing modifier keys on your keyboard like a… regular person. But it doesn’t have to be this way! You could use foot pedals instead,
as [Jan Herman] demonstrates.
Now, if you’re a diehard embedded engineer, you might be contemplating your favorite USB HID interface chip and how best to whip up a custom PCB for the job. But it doesn’t have to be that complicated! Instead, [Jan] goes for an old school hack—he simply ripped the guts out of an cheap USB keyboard. From there, he wired up a few of the matrix pads to 3.5 mm jack connectors, and put the whole lot in a little metal project box. Then, he hooked up a few foot pedal switches with 3.5 mm plugs to complete the project.
[Jan] has it set up so he can plug foot pedals in to whichever keys he needs at a given moment. For example, he can plug a foot pedal in to act as SPACE, ESC, CTRL, ENTER, SHIFT, ALT, or left or right arrow. It’s a neat way to make the project quickly reconfigurable for different productivity tasks. Plus, you can see what each pedal does at a glance, just based on how it’s plugged in.
It’s not an advanced hack, but it’s a satisfying one. We’ve seen
some other great builds in this space before, too.
If you’re cooking up your own keyboard productivity hacks, don’t hesitate to
let us know! | 24 | 15 | [
{
"comment_id": "8110283",
"author": "shinsukke",
"timestamp": "2025-03-18T20:10:24",
"content": "Ahh good old custom HID devices…Back in the day I used to play an obscure videogame called “TES 3 : Morrowind”. It had a cool exploit (not really though) where I could level up my character’s “conjurati... | 1,760,371,602.475443 | ||
https://hackaday.com/2025/03/18/the-capacitor-plague-of-the-early-2000s/ | The Capacitor Plague Of The Early 2000s | Maya Posch | [
"History"
] | [
"capacitor plague",
"electrolytic capacitor"
] | Somewhere between the period of 1999 and 2007 a plague swept through the world, devastating lives and businesses. Identified by a scourge of electrolytic capacitors violently exploding or splurging their liquid electrolyte guts all over the PCB, it led to a lot of finger pointing and accusations of stolen electrolyte formulas. In a
recent video by [Asianometry]
this story is summarized.
Blown electrolytic capacitors. (Credit: Jens Both, Wikimedia)
The bad electrolyte in the faulty capacitors lacked a suitable depolarizer, which resulted in more gas being produced, ultimately leading to build-up of pressure and the capacitor ultimately failing in a way that could be rather benign if the scored top worked as vent, or violently if not.
Other critical elements in the electrolyte are passivators, to protect the aluminium against the electrolyte’s effects. Although often blamed on a single employee stealing an (incomplete) Rubycon electrolyte formula, the video questions this narrative, as the problem was too widespread.
More likely it coincided with the introduction of low-ESR electrolytic capacitors, along with computers becoming increasingly more power-hungry, and thus stressing the capacitors in a much warmer environment than in the early 1990s. Combine this with the presence of counterfeit capacitors in the market and the truth of what happened to cause the Capacitor Plague probably involves a bit from each column, a narrative that
seems to be the general consensus
. | 54 | 15 | [
{
"comment_id": "8110271",
"author": "prosper",
"timestamp": "2025-03-18T19:37:33",
"content": "“More likely it coincided with the introduction of low-ESR electrolytic capacitors,”y’know, that really rings true. Most of the culprits I’ve seen WERE the low-ESR types. Most of the other caps on a board... | 1,760,371,602.899112 | ||
https://hackaday.com/2025/03/18/keebin-with-kristina-the-one-with-the-cheesy-keyboard/ | Keebin’ With Kristina: The One With The Cheesy Keyboard | Kristina Panos | [
"Hackaday Columns",
"Peripherals Hacks"
] | [
"90's",
"alice",
"apiaster keyboard",
"bayleaf keyboard",
"cheese board keyboard",
"draw 4 wild",
"Fox typewriter",
"GMK Panels",
"keyboards for mice",
"trackball",
"uno"
] | Let’s just kick things off in style with
the fabulously brutalist Bayleaf wireless split
from [StunningBreadfruit30], shall we? Be sure to
check out the wonderful build log/information site
as well for the full details.
Image by [StunningBreadfruit30] via
reddit
Here’s the gist: this sexy split grid of beautiful multi-jet fusion (MJF) keycaps sits on top of Kailh PG1316S switches. The CNC-machined aluminium enclosure hides nice!nano boards with a sweet little dip in each one that really pull the keyboard together.
For the first serious custom build, [StunningBreadfruit30] wanted a polished look and finish, and to that I say wow, yes; good job, and nod enthusiastically as I’m sure you are. Believe it or not, [StunningBreadfruit30] came into this with no CAD skills at all. But it was an amazing learning experience overall, and an even better version is in the works.
I didn’t read the things. Is it open-source?
It’s not, at least not at this time. But before you get too-too excited, remember that it cost $400 to build, and that doesn’t even count shipping or the tools that this project necessitated purchasing. However, [StunningBreadfruit30] says that it may be for sale in the future, although the design will have an improved sound profile and ergonomics. There’s actually a laundry list of ideas for the next iteration.
Apiaster Aims to Be the Beginner’s Endgame
That’s right —
[Saixos]’ adjustable 50-key Apiaster is designed to be endgame right from the start
, whether you’re just getting into the ergo side of the hobby, or are already deep in and are just now finding out about this keyboard. Sorry about that!
Image by [Saixos] via
reddit
So, it’s adjustable? Yes, in more ways than one. It can utilize either a single RP2040 Zero, or else one or multiple XIAO BLEs. The thumb cluster snaps off and can be moved wherever you like.
And [Saixos] didn’t stop there. In
the magnificent repo
, there’s a Python-generated case that’s highly customizable, plus MX and Choc versions of the PCB. Finally, Apiaster can use either LiPo batteries or a coin cell.
The other main crux of the biscuit here is price, and the Apiaster can be built for about $37 total minus shipping/customs/tariffs and/or tooling. That’s pretty darn good, especially if this really becomes your endgame.
The Centerfold: A ’90s Kid Works Here
Image by [nismology5] via
reddit
After using a Durgod Taurus K320 rectangle for a number of years, [nismology5] decided to lean into ergo and
acquired a Keychron Q8 with a knob and the Alice layout
after falling in love with the look of GMK Panels keycaps and the Alice herself.
Perhaps the biggest change is going from clacky blues on the Taurus to silent and slinky reds. Who knows why such a drastic change, but [nismology5] is digging the smoothness and quietude underneath those GMK Panels clones from Ali.
Now, let’s talk about that sweet trackball. It’s a Clearly Superior Technologies (CST) KidTRAC with a pool ball swapped in. They are discontinued, sadly, but at least one was available as NOS on eBay. Not to worry — they are being produced by another company out of the UK and
come in that sweet UNO Draw 4 Wild drip
.
Do you rock a sweet set of peripherals on a screamin’ desk pad?
Send me a picture
along with your handle and all the gory details, and you could be featured here!
Historical Clackers: the Fox was Quite Fetching
The lovely Fox
was named not for its primary inventor Glenn J. Barrett, but instead for company president William R. Fox. Although this may seem unfair, the Fox is a pretty great name for a good-looking typewriter.
Image via
The Classic Typewriter Page
This nineteenth-century Fox appeared in 1898, shortly after it was patented and had a number of nice features, like a notably light touch. The carriage can be removed easily for cleaning and maintenance. And the machine had a “speed escapement”, which affects the carriage advancement timing. It could be set to advance either when a typebar returns to rest, or as soon as the typebar starts off for the platen.
The first Foxes were understroke machines, which is another term for blind writer, meaning that one must lift something out of the way to see what one had written as the typebars strike the platen from underneath. In the case of the Fox, one need only turn the platen slightly.
Frontstroke or ‘visible’ typewriters were coming into vogue already, so the company introduced a frontstroke machine in 1906. It had many of the same features as the blind-writing Foxen, such as the dual-speed escapement. A one- or two-color ribbon could be used, and the machine could be set to oscillate the ribbon so as not to waste the entire bottom half as most typewriters did. I’d like to see it set to oscillate with a two-color ribbon, that’s for sure!
To capitalize on the portable craze, they built the so-called “Baby Fox” in 1917. Corona found the resemblance to their own portables quite striking and successfully sued Fox. The company went out of business in 1921, possibly because of this litigation. Ah, well.
Finally, a Keyboard for Mice
Image by [RobertLobLaw2] via
reddit
Much like the fuzzy-bezeled cat keyboard from a few Keebins ago,
[RobertLobLaw2]’s keyboard isn’t quite as cheesy as may first appear
. For one thing, most of the legends are in
this Swiss cheese-inspired font
that’s a little bit hard to read, so you’d better have your QWERTY straight.
Probably the best thing about these delicious-looking 3D-printed keycaps are the cheese knife Backspace, Enter, and right Shift along with the novelties like the mousy Esc. Underneath all that fromage is a Keychron V6 Max with unknown switches.
[RobertLobLaw2] explains that cheese and keyboards have more in common than you think, as both hobbies use ‘pretentious adjectives to describe the sensory experience (of the hobby)’. Boy, if that isn’t the thocking truth. Should you require such a charcuter-key board for yourself,
the files are freely available
.
Got a hot tip that has like, anything to do with keyboards?
Help me out by sending in a link or two
. Don’t want all the Hackaday scribes to see it? Feel free to
email me directly
. | 4 | 3 | [
{
"comment_id": "8110247",
"author": "MrSVCD",
"timestamp": "2025-03-18T18:21:02",
"content": "I really love the 90:s keyboard. The colours speak to me.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8110322",
"author": "Jim J Jewett",
"timestamp": "20... | 1,760,371,602.661709 | ||
https://hackaday.com/2025/03/18/simulating-embedded-development-to-reduce-iteration-time/ | Simulating Embedded Development To Reduce Iteration Time | Lewin Day | [
"Software Development"
] | [
"ESP32",
"programming",
"simulator"
] | There’s something that kills coding speed—iteration time. If you can smash a function key and run your code, then watch it break, tweak, and smash it again—you’re working fast. But if you have to first compile your code, then plug your hardware in, burn it to the board, and so on… you’re wasting a lot of time. It’s that problem that inspired [Larry] to create
an embedded system simulator to speed development time for simple projects.
The simulator is intended for emulating Arduino builds on iPhone and Mac hardware. For example, [Larry] shows off a demo on an old iPhone, which is simulating an ESP32 playing a GIF on a small LCD display. The build isn’t intended for timing-delicate stuff, nor anything involving advanced low-level peripherals or sleep routines and the like. For that, you’re better off with real hardware. But if you’re working on something like a user interface for a small embedded display, or just making minor tweaks to some code… you can understand why the the simulator might be a much faster way to work.
For now, [Larry] has kept the project closed source, as he’s found that it wouldn’t reasonably be possible for him to customize it for
everyone’s
unique hardware and use cases. Still, it’s a great example of how creating your own tools can ease your life as a developer. We’ve seen [Larry]’s great work around here before, like this
speedy JPEG decoder library
. | 22 | 11 | [
{
"comment_id": "8110209",
"author": "CH",
"timestamp": "2025-03-18T16:28:24",
"content": "Just a few layers of emulation occurring here….",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8110210",
"author": "Duncan Thomas",
"timestamp": "2025-03-18T16:3... | 1,760,371,602.802356 | ||
https://hackaday.com/2025/03/18/checking-in-on-the-isa-wars-and-its-impact-on-cpu-architectures/ | Checking In On The ISA Wars And Its Impact On CPU Architectures | Maya Posch | [
"ARM",
"Current Events",
"hardware",
"Interest",
"Microcontrollers"
] | [
"CPU ISA",
"instruction set architecture",
"mips",
"RISC-V",
"x86_64"
] | An Instruction Set Architecture (ISA) defines the software interface through which for example a central processor unit (CPU) is controlled. Unlike early computer systems which didn’t define a standard ISA as such, over time the compatibility and portability benefits of having a standard ISA became obvious. But of course the best part about standards is that there are so many of them, and thus every CPU manufacturer came up with their own.
Throughout the 1980s and 1990s, the number of mainstream ISAs dropped sharply as the computer industry coalesced around a few major ones in each type of application. Intel’s x86 won out on desktop and smaller servers while ARM proclaimed victory in low-power and portable devices, and for Big Iron you always had IBM’s Power ISA. Since we
last covered the ISA Wars
in 2019, quite a lot of things have changed, including
Apple shifting its desktop systems to ARM
from x86 with Apple Silicon and finally MIPS experiencing an afterlife in the form of LoongArch.
Meanwhile, six years after the aforementioned ISA Wars article in which newcomer RISC-V was covered, this ISA seems to have not made the splash some had expected. This raises questions about what we can expect from RISC-V and other ISAs in the future, as well as how relevant having different ISAs is when it comes to aspects like CPU performance and their microarchitecture.
RISC Everywhere
Unlike in the past when CPU microarchitectures were still rather in flux, these days they all seem to coalesce around a similar set of features, including out-of-order execution, prefetching, superscalar parallelism, speculative execution, branch prediction and multi-core designs. Most of the performance these days is gained from addressing specific bottlenecks and optimization for specific usage scenarios, which has resulted in such things like simultaneous multithreading (SMT) and various pipelining and instruction decoder designs.
CPUs today are almost all what in the olden days would have been called RISC (reduced instruction set computer) architectures, with a relatively small number of heavily optimized instructions. Using approaches like register renaming, CPUs can handle many simultaneous threads of execution, which for the software side that talks to the ISA is completely invisible. For the software, there is just the one register file, and unless something breaks the illusion, like when speculative execution has a bad day, each thread of execution is only aware of its own context and nothing else.
So if CPU microarchitectures have pretty much merged at this point, what difference does the ISA make?
Instruction Set Nitpicking
Within the world of ISA flamewars, the battle lines have currently mostly coalesced around topics like the pros and cons of delay slots, as well as those of compressed instructions, and setting status flags versus checking results in a branch. It is incredibly hard to compare ISAs in an apple-vs-apples fashion, as the underlying microarchitecture of a commercially available ARMv8-based CPU will differ from a similar x86_64- or RV64I- or RV64IMAC-based CPU. Here the highly modular nature of RISC-V adds significant complications as well.
If we look at where RISC-V is being used today in a commercial setting, it is primarily as simple embedded controllers where this modularity is an advantage, and compatibility with the zillion other possible RISC-V extension combinations is of no concern. Here, using RISC-V has an obvious advantage over in-house proprietary ISAs, due to the savings from outsourcing it to an open standard project. This is however also one of the major weaknesses of this ISA, as the lack of a fixed ISA along the pattern of ARMv8 and x86_64 makes tasks like supporting a Linux kernel for it much more complicated than it should be.
This has led Google to
pull initial RISC-V support from Android
due to the ballooning support complexity. Since every RISC-V-based CPU is only required to support the base integer instruction set, and so many things are left optional, from integer multiplication (M), atomics (A), bit manipulation (B), and beyond, all software targeting RISC-V has to explicitly test that the required instructions and functionality is present, or use a fallback.
Tempers are also
running hot
when it comes to RISC-V’s lack of integer overflow traps and
carry instructions
. As for whether compressed instructions are a good idea, the ARMv8 camp does not see any need for them, while the RISC-V camp is happy to defend them, and meanwhile x86_64 still happily uses double the number of instruction lengths courtesy of its CISC legacy, which would make x86_64 twice as bad or twice as good as RISC-V depending on who you ask.
Meanwhile an engineer with strong experience on the ARM side of things
wrote a lengthy dissertation
a while back on the pros and cons of these three ISAs. Their conclusion is that RISC-V is ‘minimalist to a fault’, with overlapping instructions and no condition codes or flags, instead requiring compare-and-branch instructions. This latter point cascades into a number of compromises, which is one of the major reasons why RISC-V is seen as problematic by many.
In summary, in lieu of clear advantages of RISC-V against fields where other ISAs are already established, its strong points seem to be mostly where its extreme modularity and lack of licensing requirements are seen as convincing arguments, which should not keep anyone from enjoying a good flame war now and then.
The China Angle
The Loongson 3A6000 (LS3A6000) CPU. (Credit: Geekerwan,
Wikimedia
)
Although everywhere that is not China has pretty much coalesced around the three ISAs already described, there are always exceptions. Unlike Russia’s ill-fated very-large-instruction-word
Elbrus
architecture, China’s CPU-related efforts have borne significantly more fruit. Starting with the
Loongson
CPUs, China’s home-grown microprocessor architecture scene began to take on real shape.
Originally these were MIPS-compatible CPUs. But starting with the 3A5000 in 2021, Chinese CPUs began to use the new LoongArch ISA. Described as being a ‘bit like MIPS or RISC-V’ in the
Linux kernel documentation
on this ISA, it features three variants, ranging from a reduced 32-bit version (LA32R) and standard 32-bit (LA32S) to a 64-bit version (LA64). In the current LS3A6000 CPU there are 16 cores with SMT support. In
reviews
these chips are shown to be rapidly catching up to modern x86_64 CPUs, including when it
comes to overclocking
.
Of course, these being China-only hardware, few Western reviewers have subjected the LS3A6000, or its upcoming successor the LS3A7000, to an independent test.
In addition to LoongArch, other Chinese companies are using RISC-V for their own microprocessors, such as
SpacemiT
, an AI-focused company, whose products also include more generic processors. This includes the K1 octa-core CPU which saw use in the
MuseBook
laptop. As with all commercial RISC-V-based cores out today, this is no speed monsters, and even the SiFive Premier P550 SoC gets
soundly beaten
by even a Raspberry Pi 4’s already rather long-in-the-tooth ARM-based SoC.
Perhaps the most successful use of RISC-V in China are the cores in Espressif’s popular ESP32-C range of MCUs, although here too they are the lower-end designs relative to the Xtensa Lx6 and Lx7 cores that power Espressif’s higher-end MCUs.
Considering all this, it wouldn’t be surprising if China’s ISA scene outside of embedded will feature mostly LoongArch, a lot of ARM, some x86_64 and a sprinkling of RISC-V to round it all out.
It’s All About The IP
The distinction between ISAs and microarchitecture can be clearly seen by contrasting Apple Silicon with other ARMv8-based CPUs. Although these all support a version of the same ARMv8 ISA, the magic sauce is in the
intellectual property
(IP) blocks that are integrated into the chip. These range from memory controllers, PCIe SerDes blocks, and integrated graphics (iGPU), to encryption and security features. Unless you are an Apple or Intel with your own GPU-solution, you will be licensing the iGPU block along with other IP blocks from IP vendors.
These IP blocks offer the benefit of being able to use off-the-shelf functionality with known performance characteristics, but they are also where much of the cost of a microprocessor design ends up going. Developing such functionality from scratch can pay for itself if you reuse the same blocks over and over like Apple or Qualcomm do. For a start-up hardware company this is one of the biggest investments, which is why they tend to license a fully manufacturable design from Arm.
The actual cost of the ISA in terms of licensing is effectively a rounding error, while the benefit of being able to leverage existing software and tooling is the main driver. This is why a new ISA like LoongArch may very well pose a real challenge to established ISAs in the long run, beacause it is being given a chance to develop in a very large market with guaranteed demand.
Spoiled For Choice
Meanwhile, the
Power ISA
is also freely available for anyone to use without licensing costs; the only major requirement is compliance with the Power ISA. The OpenPOWER Foundation is now also
part of the Linux Foundation
, with a range of IBM Power cores open sourced. These include the
A2O core
that’s based on the A2I core which powered the XBox 360 and Playstation 3’s Cell processor, as well as the
Microwatt reference design
that’s based on the much newer Power ISA 3.0.
Whatever your fancy is, and regardless of whether you’re just tinkering on a hobby or commercial project, it would seem that there is plenty of diversity in the ISA space to go around. Although it’s only human to pick a favorite and favor it, there’s something to be said for each ISA. Whether it’s a better teaching tool, more suitable for highly customized embedded designs, or simply because it runs decades worth of software without fuss, they all have their place. | 33 | 8 | [
{
"comment_id": "8110146",
"author": "ramzi",
"timestamp": "2025-03-18T14:11:38",
"content": "CPUs performance hit a wall around 2003. Since then, rather than addressing the problem it’s been working around it by adding more cores, more cache, more speculation (and providing unfixable backdoors to d... | 1,760,371,602.747188 | ||
https://hackaday.com/2025/03/18/writing-a-gps-receiver-from-scratch/ | Writing A GPS Receiver From Scratch | Bryan Cockfield | [
"gps hacks",
"Radio Hacks"
] | [
"gps",
"python",
"radio",
"receiver",
"RTL-SDR",
"sdr",
"software-defined radio"
] | GPS is an incredible piece of modern technology. Not only does it allow for locating objects precisely anywhere on the planet, but it also enables the turn-by-turn directions we take for granted these days — all without needing anything more than a radio receiver and some software to decode the signals constantly being sent down from space. [Chris] took that last bit bit as somewhat of a challenge and set off to
write a software-defined GPS receiver from the ground up
.
As GPS started as a military technology, the level of precision needed for things like turn-by-turn navigation wasn’t always available to civilians. The “coarse” positioning is only capable of accuracy within a few hundred meters so this legacy capability is the first thing that [Chris] tackles here. It is pretty fast, though, with the system able to resolve a location in 24 seconds from cold start and then displaying its information in a browser window. Everything in this build is done in Python as well, meaning that it’s a great starting point for investigating how GPS works and for building other projects from there.
The other thing that makes this project accessible is that the only other hardware needed besides a computer that runs Python is an RTL-SDR dongle. These inexpensive TV dongles ushered in a
software-defined radio revolution about a decade ago
when it was found that they could receive a wide array of radio signals beyond just TV. | 22 | 4 | [
{
"comment_id": "8110108",
"author": "vince",
"timestamp": "2025-03-18T12:00:19",
"content": "it was my very first experience with a bluetooth gps receiver, the special pcmcia bluetooth receiver for my laptop costs a fortune and was also one of the firsts. it could display a coordinate, wich you co... | 1,760,371,602.960674 | ||
https://hackaday.com/2025/03/18/diy-your-own-red-light-therapy-gear/ | DIY Your Own Red Light Therapy Gear | Lewin Day | [
"LED Hacks"
] | [
"led",
"red light therapy",
"skin",
"skincare"
] | There are all kinds of expensive beauty treatments on the market — various creams, zappy lasers, and fine mists of heavily-refined chemicals. For [Ruth Amos], a $78,000 LED bed had caught her eye, and she wondered if she could
recreate the same functionality on the cheap.
The concept behind [Ruth]’s build is simple enough. Rather than buy a crazy-expensive off-the-shelf beauty product, she decided to just buy equivalent functional components: a bunch of cheap red LEDs. Then, all she had to do was build these into a facemask and loungewear set to get the same supposed skin improving benefits at much lower cost.
[Ruth] started her build with a welding mask, inside which she fitted red LED strips of the correct wavelength for beneficial skin effects. She then did the same with an over-sized tracksuit, lacing it with an array of LED strips to cover as much of the body as possible. While it’s unlikely she was able to achieve the same sort of total body coverage as a full-body red light bed, nor was it particularly comfortable—her design cost a lot less—on the order of $100 or so.
Of course, you might question the light therapy itself. We’re not qualified to say whether or not red LEDs will give you better skin, but it’s
not the first time we’ve seen a DIY attempt at light therapy
. | 104 | 14 | [
{
"comment_id": "8110040",
"author": "Weasel",
"timestamp": "2025-03-18T08:08:27",
"content": "Well, looks like the times of ripping off esoteric people are gone. Now its the time to build some weird stuff and call it “beauty therapy”.Mark my words.Not long and someone will build a suit filled with ... | 1,760,371,603.361637 | ||
https://hackaday.com/2025/03/17/simple-robot-assembled-from-e-waste-actually-looks-pretty-cool/ | Simple Robot Assembled From E-Waste Actually Looks Pretty Cool | Lewin Day | [
"Robots Hacks"
] | [
"ESP32-CAM",
"led bulb",
"robot"
] | If you’re designing a robot for a specific purpose, you’re probably ordering fresh parts and going with a clean sheet design. If you’re just building for fun though, you can just go with whatever parts you have on hand. That’s how [Sorush Moradisani] approached building Esghati—
a “robot made from garbage.”
Remote viewing made easy.
The body of the robot is an old Wi-Fi router that was stripped clean, with the antenna left on for a classic “robot” look. The wheels are made out of old diffusers cut off of LED lamps. Two servos are used to drive the wheels independently, allowing the robot to be steered in a rudimentary tank-style fashion. Power is courtesy of a pair of 18650 lithium-ion cells. The brains of the robot is an ESP32-CAM—a microcontroller board which includes a built-in camera. Thanks to its onboard Wi-Fi, it’s able to host its own website that allows control of the robot and transmits back pictures from the camera. The ESP32 cam itself is mounted on the “head” on the robot for a good field of view. Meanwhile, it communicates with a separate Arduino Nano which is charged with generating pulses to run the drive servos. Code is
on Github
for the curious.
It’s not a complicated robot by any means—it’s pretty much just something you can drive around and look through the camera, at this stage. Still, it’s got plenty of onboard processing power and you could do a lot more with it. Plus, the wireless control opens up a lot of options. With that said, you’d probably get sick of the LED bulb wheels in short order—they offer precious little grip on just about any surface. Really, though, it just goes to show you how a bit of junk e-waste can make a cute robot—it almost has
Wall-E vibes
. Video after the break. | 9 | 7 | [
{
"comment_id": "8110015",
"author": "anon810",
"timestamp": "2025-03-18T05:10:28",
"content": "No son, we have wall-e at home.Wall-e at home:",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8110215",
"author": "David H",
"timestamp": "2025-03... | 1,760,371,603.13743 | ||
https://hackaday.com/2025/03/17/current-mirrors-tame-common-mode-noise/ | Current Mirrors Tame Common Mode Noise | Heidi Ulrich | [
"hardware",
"Misc Hacks",
"News",
"Science"
] | [
"diffamp",
"differential amplifier",
"long tailed pair",
"mirror",
"noise",
"oscilloscope",
"tail resistor",
"transistor"
] | If you’re the sort who finds beauty in symmetry – and I’m not talking about your latest PCB layout – then you’ll appreciate this clever take on the long-tailed pair.
[Kevin]’s video on this topic
explores boosting common mode rejection by swapping out the old-school tail resistor for a current mirror. Yes,
the humble current mirror
– long underestimated in DIY analog circles – steps up here, giving his differential amplifier a much-needed backbone.
So why does this matter? Well, in Kevin’s bench tests, this hack more than doubles the common mode rejection, leaping from a decent 35 dB to a noise-crushing 93 dB. That’s not just tweaking for tweaking’s sake; that’s taking a breadboard standard and making it ready for sensitive, low-level signal work. Instead of wrestling with mismatched transistors or praying to the gods of temperature stability, he opts for a practical approach. A couple of matched NPNs, a pair of emitter resistors, and a back-of-the-envelope resistor calculation – and boom, clean differential gain without the common mode muck.
If you want the nitty-gritty details,
schematics of the demo circuits are on his project GitHub
. Kevin’s explanation is equal parts history lesson and practical engineering, and
it’s worth the watch
. Keep tinkering, and do share your thoughts on this. | 12 | 5 | [
{
"comment_id": "8110002",
"author": "Paul",
"timestamp": "2025-03-18T04:18:02",
"content": "from a decent 35 dB to a noise-crushing 93 dB“more than doubles” indeed.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8110045",
"author": "ono",
"t... | 1,760,371,603.071104 | ||
https://hackaday.com/2025/03/17/turning-down-the-noise-on-smps/ | Turning Down The Noise On SMPS | Bryan Cockfield | [
"Tech Hacks"
] | [
"capacitance",
"diode",
"electronics",
"noise",
"power supply",
"smps",
"switch mode power supply",
"transistor"
] | On paper, electricity behaves in easy-to-understand, predictable ways. That’s mostly because the wires on the page have zero resistance and the switching times are actually zero, whereas in real life neither of these things are true. That’s what makes things like switch-mode power supplies (SMPS) difficult to build and troubleshoot. Switching inductors and capacitors tens or hundreds of thousands of times a second (or more) causes some these difficulties to arise when these devices are built in the real world. [FesZ Electronis] takes a deep dive into
some of the reasons these difficulties come up in this video
.
The first piece of electronics that can generate noise in an SMPS are the rectifier diodes. These have a certain amount of non-ideal capacitance as well as which causes a phenomenon called reverse current, but this can be managed by proper component choice to somewhat to limit noise.
The other major piece of silicon in power supplies like this that drives noise are the switching transistors. Since the noise is generally caused by the switching itself, there is a lot that can be done here to help limit it. One thing is to slow down the amount of time it takes to transition between states, limiting the transients that form as a result of making and breaking connections rapidly. The other, similar to selecting diodes, is to select transistors that have properties (specifically relating to inherent capacitances) that will limit noise generation in applications like this.
Of course there is a lot more information as well as charts and graphs in [FesZ]’s video. He’s become well-known for deep dives into practical electrical engineering topics like these for a while now. We especially like his videos about
impedance matching
as well as a more recent video where
he models a photovoltaic solar panel in SPICE
. | 13 | 5 | [
{
"comment_id": "8109954",
"author": "jenningsthecat",
"timestamp": "2025-03-18T00:36:25",
"content": "When the subject at hand is noise, it strikes me as fortunate that the switching times AREN’T “actually zero”. The faster the edge, the higher the harmonic content. Sure, fast switches are more eff... | 1,760,371,603.409543 | ||
https://hackaday.com/2025/03/17/recreating-a-braun-classic-with-3d-printing/ | Recreating A Braun Classic With 3D Printing | Lewin Day | [
"home hacks"
] | [
"Braun",
"desk fan",
"fan"
] | Braun was once a mighty pillar of industrial design; a true titan of the mid-century era. Many of the company’s finest works have been forgotten outside of coffee table books and vintage shops.
[Distracted by Design] wanted to bring one of the classics back to life—
the Braun HL70 desk fan.
The original was quite a neat little device. It made the most of simple round shapes and was able to direct a small but refreshing stream of air across one’s desk on a warm day. In reality, it was probably bought as much for its sleek aesthetics as for its actual cooling ability.
Obviously, you can’t just buy one anymore, so [Distracted by Design] turned to 3D printing to make their own. The core of the build was a mains-powered motor yanked out of a relatively conventional desk fan. However, it was assembled into a far more attractive enclosure that was inspired by the Braun HL70, rather than being a direct copy. We get a look at both the design process and the final assembly, and the results are quite nice. It feels like a 2025 take on the original in a very positive sense.
Files are available
on Printables
for the curious. It’s not the first time we’ve
contemplated fancy fans and their designs.
Video after the break. | 15 | 8 | [
{
"comment_id": "8109922",
"author": "macsimski",
"timestamp": "2025-03-17T21:56:32",
"content": "jep Dieter rahm really set a standard with brAun. i also really dig his portable radios. very simple and clean. Apple is trying to emulate this in mac os, but gloriously misses the point completely on u... | 1,760,371,603.940717 | ||
https://hackaday.com/2025/03/17/repairing-a-legendary-elka-synthex-analog-synthesizer/ | Repairing A Legendary Elka Synthex Analog Synthesizer | Maya Posch | [
"Musical Hacks",
"Repair Hacks"
] | [
"analog synthesizer"
] | Handy diagnostic LEDs on the side of the tone generator boards. (Credit: Mend it Mark, YouTube)
Somehow, an Elka Synthex analog synthesizer
made it onto [Mend it Mark]’s repair bench recently.
It had a couple of dud buttons, and some keys produced the wrong tone. Remember, this is an analog synthesizer from the 1980s, so we’re talking basic 74LS chips and kin. Fortunately, Elka helped him with the complete repair manual, including schematics.
As usual, [Mark] starts by diagnosing the faults, using the schematics to mark the parts of the circuitry to focus on. Then, the synth’s bonnet is popped open to reveal its absolutely gobsmackingly delightful inner workings, with neatly modular PCBs attached to a central backplane. The entire unit is controlled by a 6502 MPU, with basic counter ICs handling tone generation, controlled by top panel settings.
The
Elka Synthex
is a polyphonic analog synthesizer produced from 1981 to 1985 and used by famous artists, including Jean-Michel Jarre. Due to its modular nature, [Mark] was quickly able to hunt down the few defective 74LS chips and replace them before testing the instrument by playing some synth tunes from Jean-Michel Jarre’s Oxygène album, as is proper with a 1980s synthesizer.
Looking for something
simpler
? Or, perhaps, you want something
not quite that simple
. | 16 | 5 | [
{
"comment_id": "8109861",
"author": "macsimski",
"timestamp": "2025-03-17T18:33:16",
"content": "Ah. you saw that video on youtube too.Now im curious how big the venn diagram overlap is between people reading hackaday and people getting this video as a suggestion in their feed.",
"parent_id": n... | 1,760,371,603.460006 | ||
https://hackaday.com/2025/03/17/ask-hackaday-what-would-you-do-with-the-worlds-smallest-microcontroller/ | Ask Hackaday: What Would You Do With The World’s Smallest Microcontroller? | Dan Maloney | [
"Ask Hackaday",
"Hackaday Columns",
"Microcontrollers"
] | [
"arm",
"Ask Hackaday",
"bga",
"cortex",
"MCU",
"microcontroller",
"texas instruments"
] | It’s generally pretty easy to spot a microcontroller on a PCB. There are clues aplenty: the more-or-less central location, the nearby crystal oscillator, the maze of supporting passives, and perhaps even an obvious flash chip lurking about. The dead giveaway, though, is all those traces leading to the chip, betraying its primacy in the circuit. As all roads lead to Rome, so it often is with microcontrollers.
It looks like that may be about to change, though, based on Texas Instruments’
recent announcement of a line of incredibly small Arm-based microcontrollers
. The video below shows off just how small the MSPM0 line can be, ranging from a relatively gigantic TSSOP-20 case down to an eight-pin BGA package that measures only 1.6 mm by 0.86 mm. That’s essentially the size of an 0603 SMD resistor, a tiny footprint for a 24-MHz Cortex M0+ MCU with 16-kB of flash, 1-kB of SRAM, and a 12-bit ADC. The larger packages obviously have more GPIO brought out to pins, but even the eight-pin versions support six IO lines.
Of course, it’s hard not to write about a specific product without sounding like you’re shilling for the company, but being first to market with an MCU in this size range is certainly newsworthy. We’re sure other manufacturers will follow suit soon enough, but for now, we want to know how you would go about using a microcontroller the size of a resistor. The promo video hints at TI’s target market for these or compact wearables by showing them used in earbuds, but we suspect the Hackaday community will come up with all sorts of creative and fun ways to put these to use — shoutout to [mitxela], whose habit of building
impossibly small electronic jewelry
might be a good use case for something like this.
There may even be some nefarious use cases for a microcontroller this small. We were skeptical of the story about
“spy chips” on PC motherboards
, but a microcontroller that can pass for an SMD resistor might change that equation a bit. There’s also
the concept of “Oreo construction”
that these chips might make a lot easier. A board with a microcontroller embedded within it could be a real security risk, but on the other hand, it could make for some very interesting applications.
What’s your take on this? Can you think of applications where something this small is enabling? Or are microcontrollers that are likely to join the dust motes at the back of your bench after a poorly timed sneeze a bridge too far? Sound off in the comments below. | 94 | 47 | [
{
"comment_id": "8109813",
"author": "Rick",
"timestamp": "2025-03-17T17:12:59",
"content": "What Would You Do With The World’s Smallest Microcontroller?Is it markedNot for rectal use? If not, I have an idea 😛",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "... | 1,760,371,603.582965 | ||
https://hackaday.com/2025/03/17/build-your-own-air-mouse-okay/ | Build Your Own Air Mouse, Okay? | Lewin Day | [
"Peripherals Hacks"
] | [
"air mouse",
"hid",
"hid device",
"mouse"
] | Are you using a desk mouse like some kind of… normal computer user? Why, beg the heavens? For you could be using an
air mouse
, of your very own creation!
[Misfit Maker] shows the way.
Check out what he made in the video below.
An air mouse is a mouse you use in the air—which creates at least one major challenge. Since you’re not sliding along a surface, you can’t track the motion by mechanical friction like a ball mouse or by imaging as in an optical mouse. Instead, this build relies on a gyroscope sensor to track motion and translate that into pointer commands. The build relies on an ESP32-C3 as the microcontroller at the heart of things. It communicates with an MPU6050 gyroscope and accelerometer to track motion in space. It then communicates as a human interface device over Bluetooth, so you can use it with lots of different devices. The mouse buttons—plus media control buttons—are all capacitive touch-sensitive, thanks to an MPR121 touch sensor module.
There’s something neat about building your own tools to interface with the machines, almost like it helps meld the system to your whims. We see a lot of innovative
mouse
and
HID projects
around these parts. | 7 | 4 | [
{
"comment_id": "8109803",
"author": "Paul",
"timestamp": "2025-03-17T16:48:39",
"content": "Cool. Reminiscent of the Gyration Air Mouse from the turn of the century. I’m sure the new IMU is an improvement over the gyroscopes used in that one — they drifted like crazy.",
"parent_id": null,
... | 1,760,371,603.622123 | ||
https://hackaday.com/2025/03/17/relativity-space-changes-course-on-path-to-orbit/ | Relativity Space Changes Course On Path To Orbit | Tom Nardi | [
"Current Events",
"Featured",
"Slider",
"Space"
] | [
"Additive Manufacturing",
"commercial space",
"relativity space"
] | In 2015, Tim Ellis and Jordan Noone founded Relativity Space around an ambitious goal: to be the first company to put a 3D printed rocket into orbit. While additive manufacturing was already becoming an increasingly important tool in the aerospace industry, the duo believed it could be pushed further than anyone had yet realized.
Rather than assembling a rocket out of smaller printed parts, they imagined the entire rocket being produced on a huge printer. Once the methodology was perfected, they believed rockets could be printed faster and cheaper than they could be traditionally assembled. What’s more, in the far future, Relativity might even be able to produce rockets off-world in fully automated factories. It was a bold idea, to be sure. But then, landing rockets on a barge in the middle of the ocean once seemed pretty far fetched as well.
An early printed propellant tank.
Of course, printing something the size of an orbital rocket requires an exceptionally large 3D printer, so Relativity Space had to built one. It wasn’t long before the company had gotten to the point where they had successfully tested their printed rocket engine, and were scaling up their processes to print the vehicle’s propellant tanks. In 2018 Bryce Salmi, then an avionics hardware engineer at Relatively Space,
gave a talk at Hackaday Supercon
detailing the rapid progress the company had made so far.
Just a few years later, in March of 2023, the Relativity’s first completed rocket sat fueled and ready to fly on the launch pad. The Terran 1 rocket wasn’t the entirely printed vehicle that Ellis and Noone had imagined, but with approximately 85% of the booster’s mass being made up of printed parts, it was as close as anyone had ever gotten before.
The launch of Terran 1 was a huge milestone for the company, and even though a problem in the second stage engine prevented the rocket from reaching orbit, the flight proved to critics that a 3D printed rocket could fly and that their manufacturing techniques were sound. Almost immediately, Relativity Space announced they would begin work on a larger and more powerful successor to the Terran 1 which would be more competitive to SpaceX’s Falcon 9.
Now, after an administrative shakeup that saw Tim Ellis replaced as CEO, the company has
released a nearly 45 minute long video
detailing their plans for the next Terran rocket — and explaining why they won’t be 3D printing it.
Meet the New Boss
For the mainstream press, the biggest story has been that former Google chief Eric Schmidt would be taking over as Relativity’s CEO. Tim Ellis will remain on the company’s board, but likely won’t have much involvement in the day-to-day operation of the company. Similarly, co-founder Jordan Noone stepped down from chief technology officer to take on an advisory role back in 2020.
Eric Schmidt
With the two founders of the company now sidelined, and despite the success of the largely 3D printed Terran 1, the video makes it clear that they’re pursuing a more traditional approach for the new Terran R rocket. At several points in the presentation, senior Relativity staffers explain the importance of remaining agile in the competitive launch market, and caution against letting the company’s historic goals hinder their path forward. They aren’t abandoning additive manufacturing, but it’s no longer the driving force behind the program.
For his part,
The New York Times
reports
that Schmidt made a “significant investment” in Relativity Space to secure controlling interest in the company and his new position as CEO, although the details of the arrangement have so far not been made public. One could easily dismiss this move as Schmidt’s attempt to buy into the so-called “billionaire space race”, but it’s more likely he simply sees it as an investment in a rapidly growing industry.
Even before he came onboard, Relativity Space had amassed nearly $3 billion in launch contracts. Between his considerable contacts in Washington, and his time as the chair of the DoD’s Defense Innovation Advisory Board, it’s likely Schmidt will attempt to put Relativity the running for lucrative government launches as well.
All they need is a reliable rocket, and they’ll have a revenue stream for years.
Outsourcing Your Way to Space
In general, New Space companies like SpaceX and Rocket Lab have been far more open about their design and manufacturing processes than the legacy aerospace players. But even still, the video released by Relativity Space offers an incredibly transparent look at how the company is approaching the design of Terran R.
One of the most interesting aspects of the rocket’s construction is how many key components are being outsourced to vendors. According to the video, Relativity Space has contracted out the manufacturing of the aluminium “domes” that cap off the propellant tanks, the composite overwrapped pressure vessels (COPVs) that hold high pressure helium at cryogenic temperatures, and even the payload fairings.
This isn’t like handing the construction of some minor assemblies off to a local shop — these components are about as flight-critical as you can possibly get. In 2017, SpaceX famously lost one of their Falcon 9 rockets (and its payload) in an explosion on the launch pad due to a flaw in one of the booster’s COPVs. It’s believed the company ultimately brought production of COPVs in-house so they could have complete control of their design and fabrication.
Unpacking a shipment of composite overwrapped pressure vessels (COPVs) for Terran R
Farming out key components of Terran R to other, more established, aerospace companies is a calculated risk. On one hand, it will allow Relativity Space to accelerate the booster’s development time, and in this case time is very literally money. The sooner Terran R is flying, the sooner it can start bringing in revenue. The trade-off is that their launch operations will become dependent on the performance of said companies. If the vendor producing their fairings runs into a production bottleneck, there’s little Relativity Space can do but wait. Similarly, if the company producing the propellant tank domes decides to raise their prices, that eats into profits.
For the long term security of the project, it would make the most sense for Relativity to produce all of Terran R’s major components themselves. But at least for now, the company is more concerned with getting the vehicle up and running in the most expedient manner possible.
Printing Where it Counts
Currently, 3D printing a tank dome simply takes too long.
In some cases, this is where Relativity is still banking on 3D printing in the long term. As explained in the video by Chief Technology Officer Kevin Wu, they initially planned on printing the propellant tank domes out of aluminum, but found that they couldn’t produce them at a fast enough rate to support their targeted launch cadence.
At the same time, the video notes that the state-of-the-art in metal printing is a moving target (in part thanks to their own research and development), and that they are continuing to improve their techniques in parallel to the development of Terran R. It’s not hard to imagine a point in the future where Relativity perfects printing the tank domes and no longer needs to outsource them.
While printing the structural components of the rocket hasn’t exactly worked out as Relativity hoped, they are still fully committed to printing the booster’s Aeon R engines. Printing the engine not only allows for rapid design iteration, but the nature of additive manufacturing makes it easy to implement features such as integrated fluid channels which would be difficult and expensive to produce traditionally.
Printing an Aeon R engine
Of course, Relativity isn’t alone in this regard. Nearly every modern rocket engine is using at least some 3D printed components for precisely the same reasons, and they have been for some time now.
Which in the end, is really the major takeaway from Relativity’s update video. Though the company started out with an audacious goal, and got very close to reaching it, in the end they’ve more or less ended up where everyone else in aerospace finds themselves in 2025. They’ll use additive manufacturing where it makes sense, partner with outside firms when necessary, and use traditional manufacturing methods where they’ve proven to be the most efficient.
It’s not as exciting as saying you’ll put the world’s first 3D printed rocket into space, to be sure. But it’s the path that’s the most likely to get Terran R on the launch pad within the next few years, which is where they desperately need to be if they’ll have any chance of catching up to the commercial launch providers that are already gobbling up large swaths of the market. | 25 | 9 | [
{
"comment_id": "8109782",
"author": "Jan",
"timestamp": "2025-03-17T15:20:18",
"content": "regarding the huger 3D printer… I know it doesn’t work that way, but in my mind I see: a production worker walking in early in the morning seeing a misprint looking like a really huge pile of spaghetti-like m... | 1,760,371,605.851557 | ||
https://hackaday.com/2025/03/17/3d-printed-brick-layers-for-everyone/ | 3D Printed Brick Layers For Everyone | Al Williams | [
"3d Printer hacks",
"Software Hacks"
] | [
"3d printing",
"brick layers",
"slicer"
] | Some slicers have introduced brick layers, and more slicers plan to add them. Until that happens, you can use
this new script from [Geek Detour]
to get brick layer goodness on Prusa, Orca, and Bambu slicers. Check out the video below for more details.
The idea behind brick layers is that outer walls can be stronger if they are staggered vertically so each layer interlocks with the layer below it. The pattern resembles a series of interlocking bricks and can drastically increase strength. Apparently, using the script breaks the canceling object functionality in some printers, but that’s a small price to pay. Multi-material isn’t an option either, but — typically — you’ll want to use the technique on functional parts, which you probably aren’t printing in colors. Also, the Arachne algorithm option only works reliably on Prusa slicer, so far.
The video covers a lot of detail on how hard it was to do this in an external script, and we are impressed. It should be easier to write inside the slicer since it already has to figure out much of the geometry that this script has to figure out by observation.
If you want more information,
we’ve covered brick layers
(and the controversy around them) back in November. Of course,
scripts that add functions to slicers
, tend to get outdated once the
slicers catch up
. | 18 | 4 | [
{
"comment_id": "8109704",
"author": "strawberrymortallyb0bcea48e7",
"timestamp": "2025-03-17T11:34:39",
"content": "Open source can ignore patents, if you don’t resell it.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8109709",
"author": "Harvie.CZ... | 1,760,371,606.284993 | ||
https://hackaday.com/2025/03/17/a-6502-in-the-shell/ | A 6502, In The Shell | Jenny List | [
"Linux Hacks",
"Microcontrollers",
"Software Hacks"
] | [
"6502",
"shell",
"shell script"
] | Shell scripting is an often forgotten programming environment, relegated to simple automation tasks and little else. In fact, it’s possible to achieve much more complex tasks in the shell. As an example, here’s [calebccf] with an emulated 6502 system in a
busybox ash shell script
.
What’s in the emulator? A simple 6502 system with RAM, ROM, and an emulated serial port on STDIO. It comes with the wozmon Apple 1 monitor and BASIC, making for a very mid-1970s experience. There’s even a built-in monitor and debugger, which from our memories of debugging hand-assembled 8-bit code back in the day, should be extremely useful.
Although the default machine has a generous 32k of RAM and 16k ROM, you can easily adjust these limits by editing machine.sh. In addition, you can get a log of execution via a socket if you like. Don’t expect it to run too fast, and we did have to adjust the #! line to get it to run on our system (we pointed it to bash, but your results may vary).
What you use this for is up to you, but we’re sure you’ll all agree it’s an impressive feat in the shell. It’s
not the first time we’ve seen some impressive feats there, though
. Our
Linux Fu column
does a lot with the shell if you want further inspiration. | 8 | 3 | [
{
"comment_id": "8109660",
"author": "Rock Erickson",
"timestamp": "2025-03-17T09:49:24",
"content": "Shell scripting is an often forgotten programming environment, relegated to simple automation tasks and little else.I can fell a tree using 7lbs sledgehammer or e-tool, but it doesn’t mean they are ... | 1,760,371,605.904789 | ||
https://hackaday.com/2025/03/16/the-amiga-no-one-wanted/ | The Amiga No One Wanted | Al Williams | [
"Retrocomputing"
] | [
"amiga",
"doom"
] | The Amiga has a lot of fans, and rightly so. The machine broke a lot of ground. However, according to [Dave Farquhar], one of the most popular models today —
the Amiga 600
— was reviled in 1992 by just about everyone. One of the last Amigas, it was supposed to be a low-cost home computer but was really just a repackaged Amiga 1000, a machine already seven years old which, at the time, might as well have been decades. The industry was moving at lightspeed back then.
[Dave] takes a look at how Commodore succeeded and then lost their way by the time the 600 rolled out. Keep in mind that low-cost was a relative term. A $500 price tag was higher than it seems today and even at that price, you had no monitor or hard drive. So at a $1,000 for a practical system you might as well go for a PC which was taking off at the same time.
By the time Commodore closed down, they had plenty of 600s left, but they also had refurbished 500s, and for many, that was the better deal. It was similar to the 500 but had more features, like an external port and easy memory expansion. Of course, both machines used the Motorola 68000. While that CPU has a lot of great features, by 1992, the writing was on the wall that the Intel silicon would win.
Perhaps the biggest issue, though, was the graphics system. The original Amiga outclassed nearly everything at the time. But, again, the industry was moving fast. The 600 wasn’t that impressive compared to a VGA. And, as [Dave] points out, it couldn’t run
DOOM
.
There’s more to the post. Be sure to check it out. It is a great look into the history of the last of a great line of machines. Maybe if Commodore had
embraced PC interfaces
, but we’ll never know. [Dave’s] take on the end of the Amiga echos others we’ve read. It wasn’t exactly
Doom that killed the Amiga
. It was more complicated than that. But Doom would have helped. | 60 | 20 | [
{
"comment_id": "8109624",
"author": "Joshua",
"timestamp": "2025-03-17T05:29:19",
"content": "Wasn’t the A600/A1200 the stupid idea of Commodore USA?Here in Germany, by early 90s, users rather wanted more A500s and some new A2000s insteads.But no one was listening for some reason, and instead those... | 1,760,371,606.125441 | ||
https://hackaday.com/2025/03/16/wire-recording-speaks-again/ | Wire Recording Speaks Again | Al Williams | [
"Teardown"
] | [
"Mr Carlson",
"wire recorder"
] | If you think of old recording technology, you probably think of magnetic tape, either in some kind of cassette or, maybe, on reels. But there’s an even older technology that recorded voice on hair-thin stainless steel wire and [Mr. Carlson] happened upon a recorded reel of wire. Can he extract the audio from it?
Of course!
You can see and hear the results in the video below.
It didn’t hurt that he had several junk wire recorders handy, although he thought none were working. It was still a good place to start since the heads and the feed are unusual to wire recorders. Since the recorder needed a little work, we also got a nice teardown of that old device. The machine was missing belts, but some rubber bands filled in for a short-term fix.
The tape head has to move to keep the wire spooled properly, and even with no audio, it is fun to watch the mechanism spin both reels and move up and down. But after probing the internal pieces, it turns out there actually was some audio, it just wasn’t making it to the speakers.
The audio was noisy and not the best reproduction, but not bad for a broken recorder that is probably at least 80 years old. We hope he takes the time to fully fix the old beast later, but for now, he did manage to hear what was “on the wire,” even though that has a totally different meaning than it usually does.
It is difficult to
recover wire recordings
, just as it will be difficult to read modern media one day. If you want
to dive deep into the technology
, we can help with that, too. | 14 | 9 | [
{
"comment_id": "8109620",
"author": "Eric",
"timestamp": "2025-03-17T02:47:18",
"content": "Hogan’s Heroes TV series featured custom build wire recorder/player that POW used. This is the only reason I knew of it. The one used in the show is fake and audio is added to the film during editing.",
... | 1,760,371,605.734199 | ||
https://hackaday.com/2025/03/16/hackaday-links-march-16-2025/ | Hackaday Links: March 16, 2025 | Dan Maloney | [
"Hackaday Columns",
"Hackaday links",
"Slider"
] | [
"brick",
"container",
"conviction",
"crime",
"cursor",
"engine room",
"firmware",
"hackaday links",
"HP",
"learn to code",
"LLM",
"logic bomb",
"printer",
"ship",
"toner"
] | “The brickings will continue until the printer sales improve!” This whole printer-bricking thing seems to be getting out of hand with the news this week that
a firmware update caused certain HP printers to go into permanent paper-saver mode
. The update was sent to LaserJet MFP M232-M237 models (opens printer menu; checks print queue name; “Phew!) on March 4, and was listed as covering a few “general improvements and bug fixes,” none of which seem very critical. Still, some users reported not being able to print at all after the update, with an error message suggesting printing was being blocked thanks to non-OEM toner. This sounds somewhat similar to the bricked Brother printers we reported on
last week
(third paragraph).
The trouble is, some users are reporting the problem even if they had genuine HP toner installed. Disturbingly,
HP support seems to be fine with this
, saying that older HP toner “may no longer be recognized due to new security measures.” Well, there’s your problem, lady! The fix, of course, is to buy yet more genuine HP toner, even if your current cartridge still has plenty of life left in it. That’s a pretty deplorable attitude on HP’s part, and more than enough reason to disable automatic firmware updates, or better yet, just disconnect your printer from the Internet altogether.
Here’s a pro-tip for all you frustrated coders out there: no matter how hard the job gets,
planting a logic bomb in your code
is probably not the right way to go. That’s the lesson that one Davis Lu learned after being convicted of “causing intentional damage to protected computers” thanks to malicious code he planted in his employer’s system. Apparently not optimistic about his future prospects with Eaton Corp. back in 2018, Lu started adding code designed to run a series of infinite loops to delete user profiles. He also went for the nuclear option, adding code to shut the whole system down should it fail to find an Active Directory entry for him. That code was apparently triggered on the day he was fired in 2019, causing global problems for his former employer. Look, we’ve all been there; coding is often lonely work, and it’s easy to fantasize about coding up something like this and watching them squirm once they fire you. But if it gets that bad, you should probably put that effort into finding a new gig.
Then again, maybe the reason you’re dissatisfied with your coding job is that you know
some smart-ass LLM is out there waiting to tell you that you don’t know how to code
. That’s what happened to one newbie Cursor user who tried to get help writing some video game code from the AI code editor. The LLM spat back about 750 lines of code but refused to reveal the rest, and when he asked to explain why, it suggested that he should develop the logic himself so that he’d be able to understand and maintain the code, and that “Generating code for others can lead to dependency and reduced learning opportunities.” True enough, but do we really need our AI tools to cop an attitude?
And finally, if you’re anything like us, you’re really going to love
this walking tour of a container ship’s mechanical spaces
. The ship isn’t named, but a little sleuthing suggests it’s one of
the
Gülsün
-class ships
built for MSC in 2019, possibly the
MSC Mina
, but that’s just a guess. This 400-meter monster can carry 23,656 twenty-foot equivalent units, and everything about it is big. Mercifully, the tour isn’t narrated, not that it would have been possible, thanks to the screaming equipment in the engine room. There are captions, though, so you’ll at least have some idea of what you’re looking at in the immaculately clean and cavernously huge spaces. Seriously, the main engine room has to have at least a dozen floors; being on the engineering crew must mean getting your steps in every day. The most striking thing about the tour was that not a single other human being was visible during the entire hour. We suppose that’s just a testament to how automated modern vessels have become, but it still had a wonderfully creepy liminal feeling to it. Enjoy! | 5 | 5 | [
{
"comment_id": "8109594",
"author": "PWalsh",
"timestamp": "2025-03-16T23:53:18",
"content": "Damn! Like walking through the Krell machine…",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8109673",
"author": "CJay",
"timestamp": "2025-03-17T10:13:01",
... | 1,760,371,605.684195 | ||
https://hackaday.com/2025/03/16/blue-ghost-watches-lunar-eclipse-from-the-lunar-surface/ | Blue Ghost Watches Lunar Eclipse From The Lunar Surface | Maya Posch | [
"Space"
] | [
"firefly",
"Moon landing",
"solar eclipse"
] | Firefly’s Blue Ghost lander’s first look at the solar eclipse as it began to emerge from its Mare Crisium landing site on March 14 at 5:30 AM UTC. (Credit: Firefly Aerospace)
After recently landing at the Moon’s Mare Crisium, Firefly’s Blue Ghost lunar lander craft was treated to a spectacle that’s rarely observed: a total solar eclipse as seen from the surface of the Moon. This entire experience was detailed
on the Blue Ghost Mission 1 live blog.
As the company notes, this is the first time that a commercial entity has been able to observe this phenomenon.
During this event, the Earth gradually moved in front of the Sun, as observed from the lunar surface. During this time, the Blue Ghost lander had to rely on its batteries as it was capturing the solar eclipse with a wide-angle camera on its top deck.
Unlike the Blood Moon seen from the Earth, there was no such cool effect observed from the Lunar surface. The Sun simply vanished, leaving a narrow ring of light around the Earth. The reason for the Blood Moon becomes obvious, however, as the refracting of the sunlight through Earth’s atmosphere changes the normal white-ish light to shift to an ominous red.
The entire sequence of images captured can be observed in the video embedded on the live blog and below, giving a truly unique view of something that few humans (and robots) have so far been able to observe.
You can make your own
lunar eclipse
. Or, make your own
solar eclipse
, at least once a day. | 20 | 6 | [
{
"comment_id": "8109558",
"author": "TG",
"timestamp": "2025-03-16T20:44:31",
"content": "Like seeing the sunset and sunrise from every point on the terminator simultaneously",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8109559",
"author": "Hirudinea",
... | 1,760,371,605.583482 | ||
https://hackaday.com/2025/03/16/inside-a-budget-current-probe/ | Inside A “Budget” Current Probe | Al Williams | [
"Reviews",
"Teardown"
] | [
"current probe",
"owon",
"test equipment"
] | Current measurements are not as handy as voltage measurements. You typically need to either measure the voltage across something and do some math or break the circuit so a known resistor in your instrument develops a voltage your meter measures and converts for you. However, it is possible to get non-contact current probes. They are generally pricey, but [Kerry Wong] shows us
one under $200
and, thus, budget compared to similar probes. Check out the review in the video below.
The OWON unit has three ranges: 4 A, 40 A, and 400 A. It claims a resolution of 10 mA and a bandwidth of 200 kHz. It requires a 9 V battery, which [Kerry] suspects won’t last very long given the rated power consumption number, although the measured draw was not as high as claimed. The specs aren’t great — this seems to be little more than a current probe meter with a connector for an oscilloscope, but if it meets your needs, that could be acceptable.
Stay tuned for the end if you want to see the insides. There’s not much on the PCB’s top side. There’s a hall-effect sensor, some adjustment pots, and an op amp. The other side of the board has many more components, but the circuit is purely analog.
It made us wonder if we should nip down to the local cheap tool store and buy a $40 meter with similar specs. It seems like you could find a spot to tap a voltage from that and save quite a bit of money.
It is possible to create a probe that doesn’t break the bank and manages at least
2 MHz of bandwidth
. Or, make your own
for about $25
, although we can’t vouch for the specs on that one. | 10 | 3 | [
{
"comment_id": "8109550",
"author": "Ostracus",
"timestamp": "2025-03-16T19:02:26",
"content": "Well, if one ditches the oscilloscope current probes can be gotten pretty cheap.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8109574",
"author": "Hans Hille... | 1,760,371,605.779848 | ||
https://hackaday.com/2025/03/16/transmitting-wireless-power-over-longer-distances/ | Transmitting Wireless Power Over Longer Distances | Maya Posch | [
"Science"
] | [
"inductive coupling",
"wireless power transfer"
] | Proof-of-concept of the inductive coupling transmitter with the 12V version of the circuitry (Credit: Hyperspace Pirate, YouTube)
Everyone loves wireless power these days, almost vindicating [Nikola Tesla’s] push for wireless power. One reason why transmitting electricity this way is a terrible idea is the massive losses involved once you increase the distance between transmitter and receiver. That said, there are ways to optimize wireless power transfer using inductive coupling, as
[Hyperspace Pirate] demonstrates in a recent video
.
Starting with small-scale proof of concept coils, the final version of the transmitter is powered off 120 VAC. The system has 10 kV on the coil and uses a half-bridge driver to oscillate at 145 kHz. The receiver matches this frequency precisely for optimal efficiency. The transmitting antenna is a 4.6-meter hexagon with eight turns of 14 AWG wire. During tests, a receiver of similar size could light an LED at a distance of 40 meters with an open circuit voltage of 2.6 V.
Although it’s also an excellent example of why air core transformers like this are lousy for efficient remote power transfer, a fascinating finding is that intermediate (unpowered) coils between the transmitter and receiver can help to boost the range due to coupling effects. Even if it’s not a practical technology (sorry, [Tesla]), it’s undeniable that it makes for a great science demonstration.
Of course, people do charge phones wirelessly. It works, but it
trades efficiency for convenience
. Modern attempts at beaming power around seem to focus more on microwaves
or lasers
. | 25 | 11 | [
{
"comment_id": "8109516",
"author": "Paul",
"timestamp": "2025-03-16T14:48:01",
"content": "Yeah, that dipole-dipole inverse-cubelaw really bites here.Large phased array transmitters (antennas multiple wavelengths in size) and target tracking (like Energous and Ossia do) can help push that closer t... | 1,760,371,605.516698 | ||
https://hackaday.com/2025/03/16/a-look-at-the-panasonic-fs-a1fm/ | A Look At The Panasonic FS-A1FM | Al Williams | [
"Retrocomputing"
] | [
"msx",
"panasonic",
"retrocomputing"
] | MSX computers were not very common in the United States, and we didn’t know what we were missing when they were popular. [Re:Enthused] shows us what would have been a fine machine in its day: a
Panasonic FS-A1FM
. Have a look at the video below to see the like-new machine.
The machine isn’t just an ordinary MSX computer. The keyboard is certainly unique, and it has an integrated floppy drive and a 1200-baud modem. The case proudly proclaims that the floppy is both double-sided and double-density. Like most MSX computers, it had a plethora of ports and, of course, a cartridge slot. Unfortunately, the machine looks great but has some problems that have not been repaired yet, so we didn’t get to see it running properly.
He was able to get to the MSX-DOS prompt to show along with the BIOS menu. We hope he manages to get the keyboard working, and we were glad to see another computer from that era we had not seen before.
We don’t think anyone made one at the time, but we’ve seen a modern take on a
luggable MSX
. Of course, you can emulate the whole thing on a Pi and
focus on the aesthetics
. | 12 | 6 | [
{
"comment_id": "8109499",
"author": "Gareth",
"timestamp": "2025-03-16T12:47:18",
"content": "I have a fully functional A1 (it looked pretty) but couldn’t really get on with. A lost “could have been”.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8109510",... | 1,760,371,605.633893 | ||
https://hackaday.com/2025/03/16/a-hackers-approach-to-all-things-antenna/ | A Hacker’s Approach To All Things Antenna | Heidi Ulrich | [
"Radio Hacks"
] | [
"antenna",
"omnidirectional",
"RF",
"signal",
"tuning",
"wavelength"
] | When your homebrew Yagi antenna only sort-of works, or when your WiFi
can
tenna seems moody on rainy days, we can assure you: it is not only you. You can stop doubting yourself once and for all after you’ve watched the
Tech 101: Antennas webinar by [Dr. Jonathan Chisum]
.
[Jonathan] breaks it all down in a way that makes you want to rip out your old antenna and start fresh. It goes further than textbook theory; it’s the kind of knowledge defense techs use for
real
electronic warfare. And since it’s out there in bite-sized chunks, we hackers can easily put it to good use.
The key takeaway is that
antenna size matters
. Basically, it’s all about wavelength, and [Jonathan] hammers home how tuning antenna dimensions to your target frequency makes or breaks your signal. Whether you’re into omnis (for example, for 360-degree drone control) or laser-focused directional antennas for secret backyard links, this is juicy stuff.
If you’re serious about getting into
RF hacking
, watch this webinar. Then dig up
that Yagi build
, and be sure to send us your best antenna hacks. | 13 | 3 | [
{
"comment_id": "8109456",
"author": "JesterNoFool",
"timestamp": "2025-03-16T08:24:11",
"content": "It’s due to antennas & propagation (primarily) that we say, “All RF is FM (fantastic magic).”",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8109508",
... | 1,760,371,606.17835 | ||
https://hackaday.com/2025/03/15/repairing-a-kodak-picture-maker-kiosk/ | Repairing A Kodak Picture Maker Kiosk | Al Williams | [
"digital cameras hacks"
] | [
"kiosk",
"kodak"
] | Photo-printing kiosks are about as common as payphones these days. However, there was a time when they were everywhere. The idea was that if you didn’t have a good printer at home, you could take your digital files to a kiosk, pay your money, and run off some high-quality images.
[Snappiness] snagged one
, and if you’ve ever wondered what was inside of one, here’s your chance.
While later models used a Windows PC inside, this one is old enough to have a Sun computer. That also means that it had things like PCMCIA slots and a film scanner. Unfortunately, it wasn’t working because of a bad touch screen. The box was looking for a network on boot, which required some parameter changes. The onboard battery is dead, too, so you have to change the parameters on every boot. However, the real killer was the touchscreen, which the software insists on finding before it will start.
The monitor is an old device branded as a Kodak monitor and, of course, is unavailable. [Snappiness] found pictures of another kiosk online and noted that the monitor was from Elo, a common provider of point-of-sale screens. Could the “Kodak” monitor just be an Elo with a new badge? It turns out it probably was because a new Elo monitor did the trick.
Of course, what excited us was that if we found one of these in a scrap pile, it might have a Sun workstation inside. Of course, you can just boot
Solaris
on your virtual PC today. You might be surprised that Kodak
invented the digital camera
. But they failed to understand what it would mean to the future of photography. | 9 | 6 | [
{
"comment_id": "8109454",
"author": "Oliver",
"timestamp": "2025-03-16T08:05:49",
"content": "Sadly he doesnt really do anything interessting for this crowd. No screws removed, no ddeice opened, no repait. Just swapping a broken monitor.Oh he does 3d print a spring for the scanner.Still curious th... | 1,760,371,606.228852 | ||
https://hackaday.com/2025/03/15/building-a-fully-automatic-birkeland-eyde-reactor/ | Building A Fully Automatic Birkeland-Eyde Reactor | Maya Posch | [
"Science"
] | [
"birkeland-eyde",
"nitrogen fixation"
] | Ever wanted to produce nitrogen fertilizer like they did in the 1900s? In that case, you’re probably looking at the Birkeland-Eyde process, which was the first industrial-scale atmospheric nitrogen fixation process. It was eventually replaced by the Haber-Bosch and Ostwald processes. [Markus Bindhammer] covers the construction of a hobbyist-sized, fully automated reactor in
this video
.
It uses tungsten electrodes to produce the requisite arc, with a copper rod brazed onto both. The frame is made of aluminium profiles mounted on a polypropylene board, supporting the reaction vessel. Powering the whole contraption is a 24 VDC, 20 A power supply, which powers the flyback transformer for the high-voltage arc, as well as an air pump and smaller electronics, including the Arduino Uno board controlling the system.
The air is dried by silica gel before entering the reactor, with the airflow measured by a mass air flow sensor and the reaction temperature by a temperature sensor. This should give the MCU a full picture of the state of the reaction, with the airflow having to be sufficiently high relative to the arc to extract the maximum yield for this already very low-yield (single-digit %) process.
Usually, we are more interested in getting our nitrogen
in liquid form
. We’ve also looked at the
Haber-Bosch method
in the past. | 7 | 4 | [
{
"comment_id": "8109446",
"author": "Drew",
"timestamp": "2025-03-16T05:56:25",
"content": "I have been thinking about making one of these, but I was going to use an oxygen concentrator (molecular sieve) to introduce pure oxygen right at the spark that had an atmosphere of almost pure nitrogen, in ... | 1,760,371,606.704162 | ||
https://hackaday.com/2025/03/15/add-webusb-support-to-firefox-with-a-special-usb-device/ | Add WebUSB Support To Firefox With A Special USB Device | Maya Posch | [
"computer hacks",
"Security Hacks"
] | [
"firefox",
"U2F",
"WebUSB"
] | RP2040-based Pico board acting as U2F dongle with Firefox. (Credit: ArcaneNibble, GitHub)
The WebUSB standard is certainly controversial. Many consider it a security risk, and, to date, only Chromium-based browsers support it. But there is a workaround that is, ironically, supposed to increase security. The adjacent Universal 2nd Factor (U2F) standard also adds (limited) USB support to browsers. Sure, this is meant solely to support U2F USB dongles for two-factor authentication purposes, but as [ArcaneNibble]
demonstrates using U2F-compatible firmware
on a Raspberry Pi RP2040, by hijacking the
U2F
payload, this API can be used to provide WebUSB-like functionality.
The provided demo involves flashing an RP2040 (e.g., Pico board) with the
u2f-hax.u2f
firmware and loading the
index.html
page from localhost or a similar secure context. After this, the buttons on the browser page can be used to toggle an LED on the Pico board on or off. You can also read an input back from the RP2040.
This feat is made possible by the opaque nature of the U2F key handle, which means that anything can be put in this blob. This makes it a snap to pass data from the U2F dongle to the host. For the inverse, things get a bit trickier. Here the ECDSA signature is manipulated inside the ASN.1 that is returned to the dongle. Since Firefox performs no signature validation (and Chrome only does a range check), this works. The MCU also auto-confirms user presence by having the key handle start with
0xfeedface
, so the device works without user interaction. However, you do seem to get an annoying popup that immediately goes away.
Of course, this only works if you create a special USB device for this purpose. That means your normal USB devices are still secure. While we know it could be a security risk, you can do some cool things with
WebUSB
. We’ve seen
a few
projects that use it. | 7 | 6 | [
{
"comment_id": "8109406",
"author": "Cad the Mad",
"timestamp": "2025-03-15T23:18:41",
"content": "That’s very cool. It is always exciting to see ways of having a web page interact with local hardware without the hardware being on the Internet.",
"parent_id": null,
"depth": 1,
"replies"... | 1,760,371,606.66032 | ||
https://hackaday.com/2025/03/15/you-too-can-do-the-franck-hertz-experiment/ | You Too Can Do The Franck-Hertz Experiment | Al Williams | [
"Science"
] | [
"franck-Hertz",
"quantum",
"tube"
] | We talk about quantum states — that is, something can be at one of several discrete values but not in between. For example, a binary digit can be a 1 or a 0, but not 0.3 or 0.5. Atoms have quantum states, but how do we know that? That’s what the Franck-Hertz experiment demonstrates, and [stoppi] shows you how to
replicate that famous experiment
yourself.
You might need to translate the web page if your German isn’t up to speed, but there’s also a video you can watch below. The basic idea is simple. A gas-filled tube sees a large voltage across the cathode and grid. A smaller voltage connects to the grid and anode. If you increase the grid voltage, you might expect the anode current to increase linearly. However, that doesn’t happen. Instead, you’ll observe dips in the anode current.
When electrons reach a certain energy they excite the gas in the tube. This robs them of the energy they need to overcome the grid/anode voltage, which explains the dips. As the energy increases, the current will again start to rise until it manages to excite the gas to the next quantum level, at which point another dip will occur.
Why not build
a whole lab
? Quantum stuff,
at a certain level
, is weird, but this experiment seems understandable enough. | 5 | 3 | [
{
"comment_id": "8109410",
"author": "Paul",
"timestamp": "2025-03-15T23:38:27",
"content": "So, the original experiment used mercury vapour to fill the tube, andthatis the gas that is analyzed. This version seems to depend on the xenon that’s present in this particular type of tube (a thyratron).I... | 1,760,371,606.608156 | ||
https://hackaday.com/2025/03/15/putting-conductive-tpu-to-the-test/ | Putting Conductive TPU To The Test | Heidi Ulrich | [
"Parts"
] | [
"conductive",
"conductivity",
"connector",
"filament",
"strip",
"tape",
"TPU"
] | Ever pried apart an LCD? If so, you’ve likely stumbled at the unassuming zebra strip — the pliable connector that makes bridging PCB pads to glass traces look effortless. [Chuck] recently set out to test if he could
hack together his own zebra strip using conductive TPU and a 3D printer
.
[Chuck] started by printing alternating bands of conductive and non-conductive TPU, aiming to mimic the compressible, striped conductor. Despite careful tuning and slow prints, the results were mixed to say the least. The conductive TPU measured a whopping 16 megaohms, barely touching the definition of
conductivity
! LEDs stayed dark, multimeters sulked, and frustration mounted. Not one to give up, [Chuck] took to his trusty Proto-pasta conductive PLA, and got bright, blinky success. It left no room for flexibility, though.
It would appear that conductive TPU still isn’t quite ready for prime time in fine-pitch interconnects. But if you find a better filament – or fancy prototyping your own zebra strip – jump in! We’d love to hear about your attempts in the comments. | 3 | 3 | [
{
"comment_id": "8109384",
"author": "MinorHavoc",
"timestamp": "2025-03-15T20:39:29",
"content": "That Reprapper conductive TPU sounds perfect for ESD control and perhaps for soft buttons or touch-sensing inputs when using short conduction paths. For most electronic circuits though, not so much.",... | 1,760,371,606.567775 | ||
https://hackaday.com/2025/03/15/my-scammer-girlfriend-baiting-a-romance-fraudster/ | My Scammer Girlfriend: Baiting A Romance Fraudster | Maya Posch | [
"Security Hacks"
] | [
"scam"
] | Nobody likes spam messages, but some of them contain rather fascinating scams. Case in point, [Ben Tasker] recently got a few romance scam emails that made him decide to
take a poke at the scam behind these messages
. This particular scam tries to draw in marks with an attached photo (pilfered from Facebook) and fake personal details. Naturally, contacting scammers is a bad idea, and you should never provide them with any personal information if you decide to have some ‘fun’.
The games begin once you contact them via the listed email address, as they’re all sent from hacked/spoofed email accounts. After this you have to wait for the scammers to return to the campaign on their monthly cycle, so give it a few weeks. Analyzing image metadata provides some clues (e.g. the
FBMD
prefix in IPTC tags set by Meta, as well as timezone info). The IP address from the email headers pointed to a VPN being used, so no easy solution here.
After establishing contact, the scammers try to coax the mark into ‘helping’ them move to their country, with Skype out-call numbers received on [Ben]’s burner phone that seem designed to add to the realism. Then ‘disaster’ strikes and the mark is asked to transfer a lot of money to help their new ‘love’. Naturally, [Ben] wasn’t a gullible mark, and set up a few traps, including a custom domain and website that’d log any visitor (i.e. the scammer).
The scammer happily clicked the link and thus the browser language (Russian) was determined while confirming the UTC+3 timezone from the image metadata. Even more devious was inflicting Cloudflare’s much-maligned Turnstile feature that is supposed to protect websites from bots and such. This did however mostly confirm what the more basic Javascript had sussed out previously. Pinning down the location of the scammers was proving to be rather hard.
The breakthrough came when following a similar scam email that came in, with the scammers having seemingly forgotten to turn on their VPN, as this time the email headers pointed to an IP address of a Russian ISP.
Ultimately this sleuthing mostly reveals the depressing truth about these scams, in that the scammers will readily make up sob stories and pilfer people’s images from social media, all to find a few susceptible marks within the probably thousands if not millions who get sent these scam mails. The crude sophistry displayed in [Ben]’s article when it comes to photoshopping visas, passports, etc. tends to be still enough to convince those who want to believe that their soulmate just messaged them out of the blue.
As much as we’d like there to be a technological solution to scams, this is one area where only careful human ‘programming’ can help, and thus why educating everyone on the hazards of the Internet is so essential. | 21 | 10 | [
{
"comment_id": "8109295",
"author": "shinsukke",
"timestamp": "2025-03-15T14:23:59",
"content": "For shame, they couldn’t even be bothered to remove the image metadata! An of course theI have actually written quite a bit of software which uses stable diffusion, and LLMs (all locally hosted!) to mak... | 1,760,371,606.525283 | ||
https://hackaday.com/2025/03/13/britcss-write-css-with-british-english-spellings/ | BritCSS: Write CSS With British English Spellings | Maya Posch | [
"internet hacks"
] | [
"css",
"the death of the english language"
] | Everyone knows that there is only one proper English, with the rest being mere derivatives that bastardize the spelling and grammar. Despite this, the hoodlums who staged a violent uprising against British rule in the American colonies have somehow made their uncouth dialect dominant in the information technologies that have taken the world by storm these past decades. In this urgent mission to restore the King’s English to its rightful place, we fortunately have patriotic British citizens who have taken it upon themselves to correct this grave injustice. Brave citizens such as [Declan Chidlow],
whose BritCSS project
is a bright beacon in these harrowing times.
Implemented as a simple, 14 kB JavaScript script to be included in an HTML page, it allows one to write CSS files using proper spelling, such as
background-colour
and
centre
. Meanwhile harsh language such as
!important
is replaced with the more pleasant
!if-you-would-be-so-kind
. It is expected that although for now this script has to be included on each page to use BritCSS, native support will soon be implemented in every browser, superseding the US dialect version. [Declan] has also been recommended to be awarded the Order of the British Empire for his outstanding services. | 37 | 20 | [
{
"comment_id": "8108762",
"author": "Gravis",
"timestamp": "2025-03-13T23:37:47",
"content": "Sophistry.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8108766",
"author": "rclark",
"timestamp": "2025-03-13T23:43:04",
"content": "Sounds like an Ap... | 1,760,371,606.461226 | ||
https://hackaday.com/2025/03/13/have-li-ion-batteries-gone-too-far/ | Have Li-ion Batteries Gone Too Far? | Navarre Bartz | [
"Battery Hacks"
] | [
"batteries",
"design",
"European Union",
"Li-ion",
"lithium battery",
"repair",
"reuse",
"right to repair"
] | The proliferation of affordable lithium batteries has made modern life convenient in a way we could only imagine in the 80s when everything was powered by squadrons of AAs, or has it? [Ian Bogost] ponders whether
sticking a lithium in every new device
is really the best idea.
There’s no doubt, that for some applications,
lithium-based chemistries
are a critically-enabling technology. NiMH-based EVs of the 1990s suffered short range and slow recharge times which made them only useful as commuter cars, but is a flashlight really better with lithium than with a replaceable cell? When household electronics are treated as disposable, and Right to Repair is only a glimmer in the eye of some legislators, a worn-out cell in a rarely-used device might destine it to the trash bin, especially for the less technically inclined.
[Bogost] decries “the misconception that rechargeables are always better,” although we wonder why his article completely fails to mention the existence of rechargeable NiMH AAs and AAAs which are loads better than their forebears in the 90s. Perhaps even more relevantly, standardized pouch and cylindrical lithium cells are available like the venerable 18650 which we know many makers prefer due to their easy-to-obtain nature. Regardless, we can certainly agree with the author that easy to source and replace batteries are few and far between in many consumer electronics these days. Perhaps
new EU regulations
will help?
Once you’ve
selected a battery
for your project, don’t forget to
manage it
if it’s a Li-ion cell. With great power density, comes great responsibility. | 85 | 16 | [
{
"comment_id": "8108697",
"author": "Steven Clark",
"timestamp": "2025-03-13T20:19:04",
"content": "I really think we should have invented standard caps and wrapping for 18650 cells to let them be used replaceably like 20 years ago. Maybe key the caps by chemistry or something so they can’t be mix... | 1,760,371,606.832728 | ||
https://hackaday.com/2025/03/13/got-junk-then-build-this-scrappy-tea-laser/ | Got Junk? Then Build This Scrappy TEA Laser | Dan Maloney | [
"Laser Hacks"
] | [
"flyback",
"laser",
"nitrogen",
"tea",
"transversely excited atmospheric",
"ZVS"
] | A piece of glass, some bits of tinfoil, a sheet of plastic, a couple of razor blades, and a few assorted bits and bobs are all it takes to build
this TEA nitrogen laser
. Oh, and a 5,000-volt flyback supply with enough amperage to stop your heart. You’ll need that too.
Seriously, if you choose to follow [MultiverseCurator] ‘s example and build this laser, you’ll want to take the proper precautions. A transversely excited atmospheric laser is simple in concept, but there are plenty of ways for them to go wrong. Unlike the gas lasers used in laser cutters, there’s no enclosed resonator cavity or mirrors. Rather, the excitation takes place across a narrow gap between two electrodes, using atmospheric nitrogen as the lasing medium. This results in hard UV emissions, which means you can’t see them with the naked eye. Add to that the spark gap creating extremely loud discharges as the laser operates, and hazards abound. Proceed with caution.
Construction starts with a flat glass plate and a pair of large capacitors made from aluminum foil plates separated by a plastic dielectric. The razor blades are connected across the capacitors, separated by a narrow gap, with an inductor made from magnet wire in parallel. A spark gap made from nuts and bolts goes in series, and the whole assembly gets connected to a high-voltage power supply — [Multiverse] used a ZVS driver and a CRT flyback transformer with an eight-megohm resistor in series. The video below has all the build details.
It’ll take a little fiddling to get it lasing, and you’ll need something phosphorescent to see the UV light — a scrap of copy paper should do. But the results are pretty amazing for something made from scrap. If you want to take the design to the next level, you’ll want to check out
[Les Wright]’s TEA laser build
. | 24 | 9 | [
{
"comment_id": "8108678",
"author": "synch",
"timestamp": "2025-03-13T18:55:25",
"content": "I wonder if they are x-ray emitters ?",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8108689",
"author": "Bill",
"timestamp": "2025-03-13T19:44:08",
"cont... | 1,760,371,606.900531 | ||
https://hackaday.com/2025/03/13/linux-fu-use-the-source-command-luke/ | Linux Fu: Use The Source (Command), Luke | Al Williams | [
"Hackaday Columns",
"Linux Hacks",
"Slider"
] | [
"bash",
"linux",
"shell script"
] | You can argue if bash is a good programming language or not, but you can’t argue that it is a programming language. However, there are a few oddities about it that make it different from most other languages you probably know. For one thing, variables are dynamically scoped. Second, you can easily change variables in an upper scope. This leads to a problem when you want to do something like reset your path:
#!/bin/bash
#: This does NOT work
PATH=/usr/bin:/bin
Well, actually, it does work; it just doesn’t work the way you imagine it might. The key is to realize that when you execute our script (say, resetpath), a new copy of bash runs. It inherits all the variables from your shell. Now the script sets PATH for the new copy of bash. Anything else you run in that script will see your change. But when the script exits, the new copy of bash is gone and the old copy sees the same old PATH it always did.
Sometimes, this is a benefit, similar to “call by value” in other languages. However, what if you want to influence things? What’s more is that the situation is just the opposite within bash functions. For example:
#!/bin/bash
b() {
echo B: $x
x=200
}
a() {
x=100
b
echo A: $x
}
a
#: output
#: B: 100
#: A: 200
Function b has no difficulty reading and even setting variable x.
The Answer, Of
Source
Course
The answer to the first problem is to use the source command (which can be either the word source or a single period). This tells bash to avoid running a new interpreter and just pretend you’d entered all the lines in a file from the console.
This is great sometimes. Our resetpath script will actually work just fine with either of these commands:
source resetpath
. resetpath
You don’t even need the #! line, although it doesn’t hurt. However, there are a few problems.
The Catches
First, if you exit, then you exit the entire shell, not something you probably meant to do. Second, you wind up polluting the variable space of the parent. For example, if your script creates a function X, with a regular shell script, that function goes away as soon as your script stops. With a source script, function X now will live forever unless you do something about it.
Neither of these problems are insurmountable, of course, and you’ll see a few ways to address it in the example code in this post.
A Simple Example
If you spend a lot of time on the command line, you might want to have shortcut names for directories. What’s more, you might want to execute a little script when you go to particular directories or even when you leave them.
My plan is to keep a simple file in ~/.proj_dirs. To keep things simple, I’m assuming you can figure out the bash format:
PROJ_DIRS["docs"]="~/library/documents"
PROJ_DIRS["video"]="~/library/videos"
PROJ_DIRS["arduino"]="/home/alw/projects/embedded/Arduino"
. . .
The eventual goal is to replace the cd command (or, at least, allow for that). However, it would be a pain to have to write something like “source pcd arduino” every time.
The Alias Solution
The answer is pretty simple. You can create a script that can install itself as an alias. Here’s the basic flow:
#!/bin/bash
#: This is not a bash shell script
#: But needs to be sourced. However...
#: Try:
#: eval $(__project_dir.sh --__install project_dir)
if [ "$1" == "--__install" ] # this should only be called from "real" script
then
aname="$2"
if [ "$aname" == "" ]
then
aname="pcd"
fi
echo -n "alias '$aname'='source "
aname=$(realpath -s "$0")
echo "$aname'"
exit 0
fi
#: Your source script goes here
...
The idea is that if you run as a regular script with –__install, it returns the alias command. You can then eval that in, for example, a startup script (like .bashrc or .profile), and then you’ll have the alias you want. By default, the code uses pcd, although you can set up any name you like on the command line. You could even create an alias for cd if you wanted to do that.
Why Not Automatic?
You could, of course, detect if you were running normally or as a source automatically. Turns out this is somewhat finicky across shells, although if you are sure you are always using real bash, it is feasible. For example:
if [[ "${BASH_SOURCE[0]}" == "$0" ]]
then
echo I am not sourced!
fi
Variables
Once you have the basic framework, it is easy to write the scripts to read the “database” (also using source) and do the actual work. However, there is a slight problem. Once you produce all the variables you need to do the work, it leaves all that pollution in your shell’s namespace.
Of course, you could write a function to clean up everything you use, but that’s a pain and error prone, too. A better idea is to write your code in a bash function. Then you can use local variables that will go away when the function returns. That leaves you with just your function to clear up with unset.
That leads to this simple framework:
#!/bin/bash
if [[ "${BASH_SOURCE[0]}" == "$0" ]]
then
if [ "$1" == "--__install" ] # this should only be called from "real" script
then
aname="$2"
if [ "$aname" == "" ]
then
aname="pcd" # default alias name
fi
echo -n "alias '$aname'='source "
aname=$(realpath -s "$0")
echo "$aname'"
exit 0
fi
echo "You must source this script"
exit 1
fi
#: Ok your script goes here
main() {
. . .
}
#: Be sure to have this at the end
#: Actually named with underscores in the real code
#: But that upsets the rendering in browser
#: Actual code at https://gist.github.com/wd5gnr/c5681f2f7072938d5d7afe7a1e3e9132
go() {
local tmprv
main "$@"
tmprv=$?
unset main, go
return $tmprv
}
go "$@"
return $?
The very bottom calls the
go
function, which calls your main function. Then the go function destroys your main function and itself. If you create new functions that you don’t want to keep around, you’ll need to destroy them yourself. Besides, you might be creating functions you want to keep, so the framework can’t decide.
The Whole Thing
You can find the entire example on
GitHub
. Outside of the management of the alias and the variable scope, the script is unremarkable. Note the optional scripts in the directories (.dir_enter and .dir_exit) are sourced also, so they only need to be readable (-r) not executable (-x).
The only other nuance is that if you enter anything as a directory that the program doesn’t recognize, it assumes it is an actual directory, so you can use this to replace the cd command entirely if you want.
Since the script can tell if it is sourced or not, it is possible to start in the source mode and then call yourself as a normal script to do work where that makes more sense. As usual with bash, there are lots of possibilities.
We talk about
bash programming
a lot around here.
Debugging
can be helpful, although they haven’t packaged the debugger for newer versions of bash lately. | 12 | 10 | [
{
"comment_id": "8108668",
"author": "superkuh",
"timestamp": "2025-03-13T18:14:55",
"content": "The new comment spam filter is broken. You need to change your Akismet config on hackaday so that it lets people post links in comments. Or at the very least tells them when they’re being blocked instead... | 1,760,371,607.00781 | ||
https://hackaday.com/2025/03/13/hacking-a-rotary-phone/ | Hacking A Rotary Phone | Al Williams | [
"Phone Hacks"
] | [
"dial phone",
"rotary dial"
] | [Yaymukund] made an interesting observation. Old-style rotary phones were made to last and made for service. Why? Because you didn’t own them, the phone company did. There was no advantage for them for you to need a service call or a new phone. Of course, many of these old phones are still hanging around like the
GPO 746 that appears in the post
.
What do you do with an old rotary phone? In this case, you make it play a random tune whenever someone picks up the handset. As you might expect, you don’t need much of the original phone to do this. In particular, you need the handset receiver and the switch hook. We’d have liked to read the dial to select a tune, but perhaps that could be in version two.
All the components wire back to a D92732 circuit board. Finding the right wires was a bit finicky, but eventually, a Teensy, a battery pack, and an audio breakout board were in place. The rest is mostly trivial.
[Yaymukund] spent about £300, but over half of that was on tools most Hackaday readers will already have. The phone itself was £65. You can use these phones as a basis for
many projects
. Even if you want to
go mobile
. | 15 | 7 | [
{
"comment_id": "8108613",
"author": "Antron Argaiv",
"timestamp": "2025-03-13T15:32:34",
"content": "The phone itself was £65That sounds…expensive.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8108616",
"author": "Evaprototype",
"timestamp... | 1,760,371,606.951496 | ||
https://hackaday.com/2025/03/13/hackaday-europe-2025-speaker-schedule-and-official-event-page/ | Hackaday Europe 2025: Speaker Schedule And Official Event Page | Tom Nardi | [
"cons",
"Hackaday Columns",
"News"
] | [
"2025 Hackaday Europe",
"schedule",
"speakers"
] | Hackaday Europe 2025 is just days away, and we’ve got the finalized speaker schedule hot off the digital press. We’re also pleased to announce that the
event page is now officially live
, where you can find all the vital information about the weekend’s festivities in one place.
Whether you’ll be joining the fun in Berlin, or watching the live stream from home, we’ve got a fantastic lineup of speakers this year who are eager to tell us all about the projects that have been keeping them up at night recently:
Saturday Schedule
Registration and Breakfast
9:00 – 10:00
Opening Remarks
10:00 – 10:20
What if the Future [of Electronics] was Compostable?
10:30 – 11:20 (Keynote)
David Cuartielles
Manufacturing the Hackaday Supercon Badge
11:30 – 11:50
Giovanni Salinas
Seeing Through Silicon with IRIS (InfraRed, in-situ) Imaging
12:00 – 12:20
Bunnie Huang
Lunch
12:30 – 13:30
Developing a NFC Based Decentralized Payment System
13:30 – 13:50
Daniel Büchele & Andre Zibell
Hacking a Pinball Machine
14:00 – 14:40
Daniel Dakhno
Hardware Startup / Product Pitfalls
14:50 – 15:30
Sera Evcimen
Creating Light Sculptures for Fun and…Mostly for Fun
15:40 – 16:00
Erik Bosman
The Core64 – NeonPixels – 65uino Collaboration
16:10 – 16:50
Geppert, Freyermuth, & Nielsen
Make PCBs Bend Over Backwards for You: How to Design Flexible PCBs
17:00 – 17:20
Rehana Al-Soltane
More Than Motors: Decoding the Software Behind Pen Plotters and CNC Devices
17:30 – 18:10
Francis Stokes
Half-size Hacking – 0.05in Matrix Boards Under the Microscope
18:20 – 18:40
Alun Morris
Dinner
18:40 – 20:00
HEU1993 to WHY2025: Dutch Hacker Camps from the Past and the Future
20:00 – 20:40
Christel Sanders
Vectors, Pixels, Plotters and Public Participation
20:50 – 21:30
Niklas Roy
Live Performance
21:30 – 22:00
Rich Hogben & Aleksandar Bradic
Badge Hacking Ceremony
22:00 – 24:00
Time Has Run Out!
Tickets sold out a few days ago, so if you’ve got one we’ll see you soon, and if not, we will be streaming all of the Saturday talks live, so hit up Hackaday on the weekend and you can play along, at least virtually. And for back-channel chat,
join us on the Hackaday Discord #europe-2025 channel. | 0 | 0 | [] | 1,760,371,607.074285 | ||
https://hackaday.com/2025/03/13/high-speed-reservoir-computing-with-integrated-laser-graded-artificial-neurons/ | High-Speed Reservoir Computing With Integrated Laser Graded Artificial Neurons | Maya Posch | [
"Science"
] | [
"neuromorphic",
"reservoir computing"
] | So-called neuromorphic computing involves the use of physical artificial neurons to do computing in a way that is inspired by the human brain. With
photonic
neuromorphic computing these artificial neurons generally use laser sources and structures such as micro-ring resonators and resonant tunneling diodes to inject photons and modulate them akin to biological neurons.
General reservoir computing with laser graded neuron. (Credit: Yikun Nie et al., 2024, Optica)
One limitation of photonic artificial neurons was that these have a binary response and a refractory period, making them unlike the more versatile graded neurons. This has now been addressed by [Yikun Nie] et al.
with their research published
in
Optica
.
The main advantage of graded neurons is that they are capable of analog graded responses, combined with no refractory period in which the neuron is unresponsive. For the photonic version, a quantum dot (QD) based gain section was constructed, with the input pulses determining the (analog) output.
Multiple of these neurons were then combined on a single die, for use in a
reservoir computing
configuration. This was used with a range of tests, including arrhythmia detection (98% accuracy) and handwriting classification (92% accuracy). By having the lasers integrated and the input pulses being electrical in nature, this should make it quite low-power, as well as fast, featuring 100 GHz QD lasers. | 2 | 2 | [
{
"comment_id": "8108567",
"author": "ono",
"timestamp": "2025-03-13T12:12:33",
"content": "Wonderful. Where is the 555 ?",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8108818",
"author": "eresonance",
"timestamp": "2025-03-14T03:57:18",
"content"... | 1,760,371,607.121504 | ||
https://hackaday.com/2025/03/15/hackaday-europe-2025-streaming-live/ | Hackaday Europe 2025: Streaming Live | Tom Nardi | [
"cons",
"News"
] | [
"2025 Hackaday Europe",
"live steam"
] | Hackaday Europe 2025 is in full swing, and whether you’re experiencing it live in Berlin or following along from home, here’s where you’ll find all the info you need to get the most out of it.
Event Page:
https://hackaday.io/europe2025
Chat:
Hackaday Discord
(Channels:
europe-2025
/
badge-hacking
)
Talk Streams:
https://www.youtube.com/@hackaday/streams | 3 | 2 | [
{
"comment_id": "8109276",
"author": "CJay",
"timestamp": "2025-03-15T13:04:36",
"content": "Well that’s my day sorted.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8109286",
"author": "Jan Prägert",
"timestamp": "2025-03-15T13:32:01",
... | 1,760,371,607.266174 | ||
https://hackaday.com/2025/03/15/probably-the-simplest-sequencing-synth/ | Probably The Simplest Sequencing Synth | Jenny List | [
"classic hacks",
"Musical Hacks"
] | [
"4017",
"555",
"cmos",
"synthesiser"
] | With inexpensive microntrollers capable of the most impressive feats of sound synthesis, it’s not so often we see projects that return to an earlier style of electronic music project. The 1-bit synth from [Electroagenda]
takes us firmly into that territory
, employing that most trusty of circuits, a 555.
It’s a time-honored circuit, a 555 provides a note clock that drives a 4017 that functions as a sequencer. This switches in a set of voltage dividers, which in turn control another 555 oscillator that produces the notes. It’s a fun toy straight from the 1970s, right down to the protoboard and hookup wire construction. There’s a demo video with some lovely beeps below, and we think most of you should have what it takes to make your own.
If you’re seeking more inspiration, may we introduce you to our
Logic Noise
series? | 31 | 16 | [
{
"comment_id": "8109260",
"author": "Jan",
"timestamp": "2025-03-15T11:23:48",
"content": "The sequencer should be 8, 12 or 16 steps. Not 10.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8109262",
"author": "ono",
"timestamp": "2025-03-15T... | 1,760,371,607.45638 | ||
https://hackaday.com/2025/03/14/make-your-cheap-thermal-camera-into-a-microscope/ | Make Your Cheap Thermal Camera Into A Microscope | Al Williams | [
"digital cameras hacks"
] | [
"ir camera",
"microscope",
"thermal camera"
] | [Project 326] has a cheap thermal camera that plugs into a smart phone. Sure they are handy, but what if you could hack one into a microscope with a resolution measured in microns? It is
easier than you might think
and you can see how in the video below.
Of course, microscopes need lenses, but glass doesn’t usually pass IR very well. This calls for lenses made of exotic material like germanium. One germanium lens gives some magnification. However, using a 3D printed holder, three lenses are in play, and the results are impressive.
The resolution is good enough to see the turns of wire in an incandescent light bulb. A decapsulated power transistor was interesting to view, too. Imaging heat at that much resolution gives you a lot of information. At the end, he teases that using first surface mirrors, he may show how to build an IR telescope as well.
Presumably, this will work with just about any IR camera if you adapt the lens holder. The unit in the video is a UNI-T UTi-260M. So when he says he spent about $35 on the build, that’s not including the $400 or so camera module.
IR imaging can pull off some amazing tricks, like
looking inside an IC
. If the thermal camera used in the video isn’t to your liking, there are plenty of
others out there
. | 17 | 5 | [
{
"comment_id": "8109223",
"author": "helge",
"timestamp": "2025-03-15T07:07:25",
"content": "No need for devices under test to warm up until the false color view occasionally provides higher contrast.With periodic pulsing and some post-processing, spatial resolution and contrast can be improved (lo... | 1,760,371,607.377233 | ||
https://hackaday.com/2025/03/14/building-a-ten-hundred-key-computer-word-giving-thing/ | Building A Ten-Hundred Key Computer Word-Giving Thing | Dan Maloney | [
"Peripherals Hacks"
] | [
"dye sublimation",
"keyboard",
"keycaps",
"word",
"xkcd"
] | From the styling of this article’s title, some might assume that the Hackaday editors are asleep at the switch this fine day. While that might be true — it’s not our turn to watch them — others will recognize this tortured phrasing as one way to use the 1,000 most commonly used words in the English language to describe a difficult technical project, such as
[Attoparsec]’s enormous and enormously impractical ten-hundred word keyboard
.
While the scale of this build is overwhelming enough, the fact that each key delivers a full word rather than a single character kind of throws the whole keyboard concept out the window. The 60×17 matrix supports the
1,000 most common English words
along with 20 modifier keys, which allow a little bit of cheating on the 1-kiloword dictionary by letting you pluralize a word or turn it into an adjective or adverb. Added complexity comes from the practical limits of PCB fabrication, which forces the use of smaller (but still quite large) PCBs that are connected together. Luckily, [Attoparsec] was able to fit the whole thing on five identical PCBs, which were linked together with card-edge connectors.
The list of pain points on this six-month project is long, and the video below covers them all in detail. What really stood out to us, though, was the effort [Attoparsec] put into the keycaps. Rather than 3D printing his own, he used dye sublimation to label blank keycaps with the 1,000 words. That might sound simple, but he had to go through a lot of trial and error before getting a process that worked, and the results are quite nice. Another problem was keeping the key switches aligned while soldering, which was solved with a 3D printed jig. We also appreciate the custom case to keep this keyboard intact while traveling; we’re going to keep that build-your-own road case service in mind for future projects.
This mega-keyboard is a significant escalation from [Attoparsec]’s
previous large keyboard project
. The results are pretty ridiculous and impractical, but that’s just making us love it more. The abundance of tips and tricks for managing a physically expansive project are just icing on the cake. | 18 | 15 | [
{
"comment_id": "8109179",
"author": "echodelta",
"timestamp": "2025-03-15T02:44:33",
"content": "First I thought it’d work for the precursor of modern Japanese or Chinese where they had thousands of pictograms for words, but then I realized it would also work for all the important but hard to see p... | 1,760,371,607.32111 | ||
https://hackaday.com/2025/03/14/cp-combining-the-usefulness-of-c-with-the-excellence-of-prolog/ | C+P: Combining The Usefulness Of C With The Excellence Of Prolog | Maya Posch | [
"Software Development"
] | [
"c++",
"prolog"
] | In a move that will absolutely not over-excite anyone, nor lead to any heated arguments, [needleful] posits that their
C Plus Prolog (C+P for short) programming language
is the best possible language ever. This is due to it combining the best of the only good programming language (Prolog) with the best of the only useful programming language (C). Although the resulting mash-up syntax that results may trigger Objective-C flashbacks, it’s actually valid
SWI-Prolog
, that is subsequently converted to C for compilation.
Language flamewars aside, the motivation for C+P as explained in the project’s README was mostly the exploring of macros in a system programming language. More specifically, by implementing a language-within-a-language you can add just about any compile-time feature you want including – as demonstrated in C+P – a form of generics. Even as a way to have a bit of fun, C+P comes dangerously close to being a functional prototype. Its main flaw is probably the lack of validation and error messages, which likely leads to broken C being generated.
Also mentioned are the
Nim
and
Haxe
languages which can be compiled (transpiled) to C or C++, which is somewhat of a similar idea as C+P, as well as
cmacro
(based on Common Lisp) and the D language. | 7 | 6 | [
{
"comment_id": "8109154",
"author": "CMH62",
"timestamp": "2025-03-15T00:51:03",
"content": "Somebody’s channeling their inner Brian Benchoff!! 😆",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8109242",
"author": "Andrew",
"timestamp": "2025-03-15T0... | 1,760,371,607.499139 | ||
https://hackaday.com/2025/03/14/pi-hand-is-a-digital-display-of-a-different-sort/ | Pi Hand Is A Digital Display Of A Different Sort | Tom Nardi | [
"Microcontrollers",
"Robots Hacks"
] | [
"Pi",
"Pi day",
"robotic hand"
] | Hackers enjoy a good theme, and so it comes as no surprise that every time March 14th (Pi Day) rolls around, the tip line sees an uptick in mathematical activity. Whether it’s something they personally did or some other person’s project they want to bring to our attention, a lot of folks out there are very excited about numbers today.
One of our most prolific circumference aficionados is [Cristiano Monteiro], who, for the last several years, has put together a special project to commemorate the date. For 2025, he’s come up with a
robotic hand that will use its fingers to show the digits of Pi
one at a time. Since there’s only one hand, anything higher than five will be displayed as two gestures in quick succession, necessitating a bit of addition on the viewer’s part.
[Cristiano] makes no claims about the anatomical accuracy of his creation. Indeed, if your mitts look anything like this, you should seek medical attention immediately. But whether you think of them as fingers or nightmarish claws, it’s the motion of the individual digits that matter.
To that end, each one is attached to an MG90 servo, which an Arduino Nano drives with attached Servo Shield. From there, it’s just a matter of code to get the digits wiggling out the correct value,
which [Cristiano] has kindly shared
for anyone looking to recreate this project.
If you’re hungry for more Pi, the
ghostly display that [Cristiano] sent in last year
is definitely worth another look. While not directly related to today’s mathematical festivities, the
portable GPS time server he put together back in 2021
is another fantastic build you should check out. | 8 | 5 | [
{
"comment_id": "8109081",
"author": "Wally Hulea",
"timestamp": "2025-03-14T20:20:21",
"content": "You could have the hand talk in ASCII, just have the thumb indicate if it’s the lower value nibble of the byte or the upper nibble value of the byte. Ignore the upper nibble if the characters are in t... | 1,760,371,607.664431 | ||
https://hackaday.com/2025/03/14/hackaday-podcast-episode-312-heart-attacks-the-speed-of-light-and-self-balancing/ | Hackaday Podcast Episode 312: Heart Attacks, The Speed Of Light, And Self-balancing | Al Williams | [
"Hackaday Columns",
"Podcasts",
"Slider"
] | [
"Hackaday Podcast"
] | Elliot does the podcast on the road to Supercon Europe, and Al is in the mood for math and nostalgia this week. Listen in and find out what they were reading on Hackaday this week.
The guys talked about the ESP-32 non-backdoor and battery fires. Then it was on to the hacks.
Self-balancing robots and satellite imaging were the appetizers, but soon they moved on to Kinect cameras in the modern day. Think you can’t travel at the speed of light? Turns out that maybe you already are.
Did you know there was a chatbot in 1957? Well, sort of. For the can’t miss stories: watches monitor your heart and what does the number
e
really mean?
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Download in DRM-free MP3 and stream it on the big speakers
.
Where to Follow Hackaday Podcast
Places to follow Hackaday podcasts:
iTunes
Spotify
Stitcher
RSS
YouTube
Check
out our Libsyn landing page
Episode 312 Show Notes:
News:
The ESP32 Bluetooth Backdoor That Wasn’t
Open Safety In The Auto Business: Renault Shares Its Battery Fire Suppression Tech
Hackaday Europe 2025 Welcomes David Cuartielles, Announces Friday Night Bring-a-Hack
What’s that Sound?
We had a ton of answers this week, and many of them were correct. It was a disposable film camera being wound and shot. Congratulations to [Bobby Tables] for getting the correct answer and winning the webcam-driven dice toss.
Interesting Hacks of the Week:
Taming The Wobble: An Arduino Self-Balancing Bot
PIDDYBOT – A Self Balancing Teaching Tool
Building A Self-Balancing Robot Made Easy
Self-balancing Arduino Does It Without An IMU
Yet Another Self-Balancing Unicycle
Self-balancing Robot Keeps Things On The Straight And Narrow
https://en.wikipedia.org/wiki/Model_predictive_control
https://github.com/kerrj/segway
Satellite Imagery You Can Play With
The Strange Afterlife Of The Xbox Kinect
You Are Already Traveling At The Speed Of Light
Lies, Damned Lies, And IGBT Datasheets
Fictional Computers: EMERAC Was The Chatbot Of 1957
Quick Hacks:
Elliot’s Picks:
FlyingCam Is A Sweet DIY Webcam On A Stick
How To Use LLMs For Programming Tasks
Some Useful Notes On The 6805-EC10 Addressable RGB LED
Al’s Picks:
Classy Paper Tape Reader Complements Homebrew Retrocomputer
What’s Wrong With This Antenna Tuner?
Clock Mechanism Goes Crazy For Arduino
Can’t-Miss Articles:
Pixel Watch 3’s Loss Of Pulse Detection: The Algorithms That Tell Someone Is Dying
You Know Pi But Do You Really Know E? | 7 | 3 | [
{
"comment_id": "8109090",
"author": "Dude",
"timestamp": "2025-03-14T20:46:38",
"content": "The problem with “It’s going to take our jobs” IS exactly that it did, and people had to shift to doing other stuff. It did happen, and it keeps on happening. Guess what – eventually we’ll run out of “other ... | 1,760,371,607.546916 | ||
https://hackaday.com/2025/03/14/you-know-pi-but-do-you-really-know-e/ | You Know Pi, But Do You Really Know E? | Al Williams | [
"Featured",
"Interest",
"Misc Hacks",
"Slider"
] | [
"e",
"mathematics",
"Pi day"
] | Pi Day is here! We bet that you know that famous constant to a few decimal points, and you could probably explain what it really means: the ratio of a circle’s circumference to its diameter. But what about the constant e? Sure, you might know it is a transcendental number around 2.72 or so. You probably know it is the base used for natural logarithms. But what does it mean?
The poor number probably needed a better agent. After all, pi is a fun name, easy to remember, with a distinctive Greek letter and lots of pun potential. On the other hand, e is just a letter. Sometimes it is known as Euler’s number, but Leonhard Euler was so prolific that there is also Euler’s constant and a set of Euler numbers, none of which are the same thing. Sometimes, you hear it called Napier’s constant, and it is known that Jacob Bernoulli discovered the number, too. So, even the history of this number is confusing.
But back to math, the number e is the base rate of growth for any continually growing process. That didn’t help? Well, consider that many things grow or decay through growth. For example, a bacteria culture might double every 72 hours. Or a radioactive sample might decay a certain amount per century.
Classic
The classic example is compound interest. Suppose you have $100, and you put it in the bank for a 10% per year return (please tell us where we can find that, by the way). So at the end of the year, we have $110, right? But what if you compound it every six months?
To figure that out, you look at the $100 after six months. The annual interest on the money is still $10, but we are only at 6 months, so prorated, that $5. Therefore, after six months, we have $105. At the end of the year, we look at the 10% of $105 ($10.50). That’s still for a year, so we need to halve it ($5.25) and add it in (
$105+105.25=110.25
). So, compounding every six months means we get an extra quarter compared to simple interest.
What if it was compounded monthly? Now, we divide our interest by 12, but we have a little more money every month. After the first month, we have $100.83 (
$100.00 + 10/12
). The second month’s net is $101.67. By the end of the year, you have $110.47. Not quite twice as much extra as you had before.
So what if you could compound weekly? Or daily? Or hourly? Generally, you’ll get more, at least up to a point. Eventually, the interest will be split up so much that it will balance the increase and, at that point, you won’t make any more. There is an upper limit to how much money we can have at the end of the year at 10%, no matter how often you compound the interest.
So Where’s e?
Assume you could get a 100% return on your money (definitely let us know how to do that). That means if you go for a year, that’s a return of 2 — you double your money. But if you split the year in half and compound, you get 2.25 times the original amount. You can try a few more splits, and you’ll find the equation for growth is
(1+1/n)
n
. That is, if you only compute it once (n=1), you get double (1+1). If you compute interest twice, you get 2.25 (that is,
(1+1/2)
2
)
.
If you set n to 1,000, the return will be 2.7169. That’s even better than 2.25. So 100,000 should be wildly better, right? Not so much. At 100,000 you get a 2.71814 return. At 10,000,000 the rate is 2.71828 (or so).
Look at those numbers. Going from 1,000 to 10,000,000 only increases yield by about 0.001. If you know calculus, you might know how to take the limit of the growth equation. If not, you can still see it is going to top off at around 2.718. Those are the first digits of e.
Of course, e is like pi — transcendental — so you can’t ever get all the digits. You just keep getting closer and closer to the actual value. But 2.718 is pretty close for practical purposes.
Scaling
We can scale e to whatever problem we have at hand. We just have to be mindful of the starting amount, the rate, and what a time period means. For example, to work with our 10% rate (instead of 100%) we have to consider the rate e
0.10
or about 1.105. Then, to scale for amounts, we have to multiply by the rate. So remember our $100 at 10% example? Our maximum return is
100 x 1.105 = 110.50
. Why did we only get $110.47? Because we compounded 12 times. The $110.50 result is the maximum.
More Years
You can also multiply the rate by the number of periods. So if we left the money in for five years: 100 x e
(0.10 x 5)
. If you think about it, then, making 50% for one year has the same maximum as making 10% for 5 years (or 25% for 2 years).
Negative Growth?
Suppose you have 120 grams of some radioactive material that decays at a rate of 50% per year. How much will be left after three years? Simplistically, it seems like the answer is that it will be depleted after two years. But that’s not true.
Just as compounding adds more money, a decay rate removes some of the radioactive material, meaning the absolute decay rate gets slower and slower with time because it is a percentage of the radioactive material’s mass.
Just for the sake of an example, suppose at some imaginary small period, the sample is at 100 grams and, thus, the decay rate is 50 grams/year. Later, the sample is at 80 grams. The decay rate is 40 grams/year, so it will take longer to go from 80 to 60 than it did to go from 100 to 80.
In this case, the rate is negative, so the formula will be
120 x e
(-0.5 x 3)
. That means you will have about 26.8 grams of radioactive material left in three years.
Modeling
Consider the classic equation for an RC circuit:
Vc=Vs(1-e
(-t/(RC))
)
. Here, Vc is the capacitor voltage, Vs is the supply voltage, t is in seconds, and RC is the product of the resistance in ohms and the capacitance in farads.
What can we infer from this? Well, you could also write this as:
Vc=Vs-Vs x e
(-t/(RC))
. Looking at our earlier model for money, it is plain that Vs is the voltage we start with, t is the time, and rate is -1/RC (time can’t be negative, after all). That makes sense because RC is the time constant in seconds, so 1/RC is the rate per second. The formula tells us how much voltage is charged in the capacitor, and subtracting that from Vs gives us the voltage drop across the capacitor.
Think about this circuit:
The circuit at t=0.5
The circuit at t=1
At t=0, we have Vs(1-e
0
), which is 0. At t=0.5, the voltage should be about 7.86V; at t=1, it should be up to 10.57V. As you can see, the
simulation
matches the math well enough.
Discharging is nearly the same:
Vc=V0 x e
(-t/(RC))
. Obviously, V0 is the voltage you started with and, again -1/RC is the rate.
So Now You Know!
There’s a common rule of thumb that after a time period (RC) a capacitor will charge to about 63% or discharge to about 37%. Now that you know the math, you can see that
e
-1
=0.37
and
1-e
-1
=0.63
. If you want to do the actual math, you can always
set up a spreadsheet
.
Anything that grows or shrinks exponentially is a candidate for using an equation involving e. That’s why it is a common base for
logarithms
. Of course, most slide rules use logarithms, but not
all of them do
.
(Title image showing e living in pi’s shadow adapted from “Pi” by [Taso Katsionis] via Unsplash.) | 29 | 12 | [
{
"comment_id": "8109034",
"author": "rclark",
"timestamp": "2025-03-14T17:37:48",
"content": "I just finished a book on the story of e. Fascinating how even used in general and then on to e with complex numbers like Euler’s e^i*π+1=0 to tie the fundamental constants together.",
"parent_id": n... | 1,760,371,607.619327 | ||
https://hackaday.com/2025/03/14/utahs-forge-a-research-laboratory-for-enhanced-geothermal-systems/ | Utah’s FORGE: A Research Laboratory For Enhanced Geothermal Systems | Maya Posch | [
"Science"
] | [
"geothermal energy"
] | Geothermal heat is a tantalizing source of energy that’s quite literally right below our feet. At the same time geothermal energy is hard to develop as the Earth’s crust is too thick in most places, limiting this to areas where magma is close enough to the surface and the underground rock permeable enough for water. The
Utah FORGE facility
is a field site were researchers are developing and testing ways to increase the scope of geothermal energy.
An Enhanced Geothermal System (
EGS
) is designed to be capable of using geothermal energy where this is normally not feasible through a technique that’s reminiscent of the hydraulic fracturing (‘fracking’) used by the oil and gas industry, but rather than creating more fractures, it instead uses hydro-shearing to prop open existing fractures and thus create the through-flow of water needed to extract geothermal energy.
So far
FORGE
has reported the successful creation of a geothermal reservoir where before there was none. This facility is located in the Milford valley in southwest Utah, which has some hydrothermal activity at the nearby Roosevelt Hot Springs, but through EGS other parts of this valley and similar areas could conceivably be used for generating electricity and for community heating as well. In a
2024 study
by University of Utah scientists, it is described how the Milford valley’s volcanic past has left a large body of magma below a thick barrier of granitic rock that could provide access to geothermal resources with EGS to create the requisite fluid permeability.
FORGE is not the only facility working on EGS, but many other sites around the world having ceased activities after issues ranging from induced seismicity, susceptibility to earthquakes and budget shortages. Much like fracking, EGS is likely to cause earthquakes. Whether EGS can be made economically feasible still remains to be seen.
Image Credit: Eric Larson, Flash Point SLC | 6 | 2 | [
{
"comment_id": "8109004",
"author": "Clancydaenlightened",
"timestamp": "2025-03-14T16:04:08",
"content": "Well if you dig a super deep bore holeThen insert two pipes one nested inside the otherPump water in one pipe, the other provides steamAtleast the bottom of the super deep bore hole in Russia ... | 1,760,371,607.705246 | ||
https://hackaday.com/2025/03/14/this-week-in-security-the-x-ddos-the-esp32-basementdoor-and-the-camelcase-rce/ | This Week In Security: The X DDoS, The ESP32 Basementdoor, And The CamelCase RCE | Jonathan Bennett | [
"Hackaday Columns",
"News",
"Security Hacks",
"Slider"
] | [
"Basementdoor",
"camelCase",
"ddos",
"This Week in Security"
] | We would be remiss if we didn’t address
the X Distributed Denial of Service (DDoS) attack that’s been happening this week
. It seems like everyone is is trying to make political hay out of the DDoS, but we’re going to set that aside as much as possible and talk about the technical details. Elon made an early statement that X was down due to a cyberattack, with the source IPs tracing back to “the Ukraine area”.
The latest reporting seems to conclude that this was indeed a DDoS, and
a threat group named “Dark Storm” has taken credit for the attack
. Dark Storm does not seem to be of Ukrainian origin or affiliation.
We’re going to try to read the tea leaves just a bit, but remember that about the only thing we know for sure is that X was unreachable for many users several times this week. This is completely consistent with the suspected DDoS attack. The quirk of modern DDoS attacks is that the IP addresses on the packets are never trustworthy.
There are two broad tactics used for large-scale DDoS attacks, sometimes used simultaneously. The first is the simple botnet. Computers, routers, servers, and cameras around the world have been infected with malware, and then remote controlled to create massive botnets. Those botnets usually come equipped with a DDoS function, allowing the botnet runner to task all the bots with sending traffic to the DDoS victim IPs. That traffic may be UDP packets with spoofed or legitimate source IPs, or it may be TCP Synchronization requests, with spoofed source IPs.
The other common approach is the
reflection or amplification attack
. This is where a public server can be manipulated into sending unsolicited traffic to a victim IP. It’s usually DNS, where a short message request can return a much larger response. And because DNS uses UDP, it’s trivial to convince the DNS server to send that larger response to a victim’s address, amplifying the attack.
Put these two techniques together, and you have a botnet sending spoofed requests to servers, that unintentionally send the DDoS traffic on to the target. And suddenly it’s understandable why it’s so difficult to nail down attribution for this sort of attack. It may very well be that a botnet with a heavy Ukrainian presence was involved in the attack, which at the same time doesn’t preclude Dark Storm as the originator. The tea leaves are still murky on this one.
That ESP32 Backdoor
As Maya says,
It Really Wasn’t
a backdoor. The
Bleeping Computer article
and
Tarlogic press release
have both been updated to reflect the reality that this wasn’t really a backdoor. Given that the original research and presentation were in Spanish, we’re inclined to conclude that the “backdoor” claim was partially a translation issue.
The terminology storm set aside,
what researchers found really was quite interesting
. The source of information was official ESP32 binaries that implement the Bluetooth HCI, the Host Controller Interface. It’s a structured format for talking to a Bluetooth chip. The official HCI has set aside command space for vendor-specific commands. The “backdoor” that was discovered was this set of undocumented vendor-specific commands.
These commands were exposed over the HCI interface, and included low-level control over the ESP32 device. However, for the vast majority of ESP32 use cases, this interface is only available to code already running on the device, and thus isn’t a security boundary violation. To Espressif’s credit,
their technical response does highlight
the case of using an ESP32 in a hosted mode, where an external processor is issuing HCI commands over something like a serial link. In that very narrow case, the undocumented HCI commands could be considered a backdoor, though still requires compromise of the controlling device first.
All told, it’s not particularly dangerous as a backdoor. It’s a set of undocumented instructions that expose low-level functions, but only from inside the house. I propose a new term for this: a Basementdoor.
The Fake Recruitment Scam
The fake recruitment scam isn’t new to this column, but this is the first time we’ve covered
a first-hand account of it
. This is the story of [Ron Jansen], a freelance developer with impressive credentials. He got a recruiter’s message, looking to interview him for a web3 related position. Interviews often come with programming tasks, so it wasn’t surprising when this one included instructions to install something from Github using
npm
and do some simple tasks.
But then, the recruiter and CTO both went silent, and [Ron] suddenly had a bad feeling about that
npm install
command. Looking through the code, it looked boring, except for the dependency NPM package,
process-log
. With only 100-ish weekly downloads, this was an obvious place to look for something malicious. It didn’t disappoint, as this library pulled an obfuscated blob of JSON code and executed it during install. The deobfuscated code establishes a websocket connection, and uploads cookies, keychains, and any other interesting config or database files it can find.
Once [Ron] new he had been had, he started the infuriating-yet-necessary process of revoking API keys, rotating passwords, auditing everything, and wiping the affected machine’s drive. The rest of the post is his recommendations for how to avoid falling for this scam yourself. The immediate answer is to run untrusted code in a VM or sandbox. There are tools like
Deno
that can also help, doing sandboxing by default. Inertia is the challenge, with a major change like that.
Camel CamelCase RCE
Apache Camel is a Java library for doing Enterprise Integration Patterns. AKA, it’s network glue code for a specific use case. It sends data between endpoints, and uses headers to set certain options. One of the important security boundries there is that internal headers shouldn’t be set by outside sources. To accomplish that, those headers are string compared with
Camel
and
org.apache.camel
as the starting characters. The problem is that the string comparison is exact, while the header names themselves are not case sensitive. It’s
literally a camelCase vulnerability
. The result is that all the internal headers are accessible from any client, via this case trickery.
The vulnerability has been fixed in the latest release of Camel. The seriousness of this vulnerability depends on the component being connected to. Akamai researchers provided a sample application, where the headers were used to construct a command. The access to these internal values makes this case an RCE. This ambiguity is why the severity of this vulnerability is disputed.
Bits and Bytes
Researchers at Facebook have
identified a flaw in the FreeType font rending library
. It’s a integer underflow leading to a buffer overflow. An attacker can specify a very large integer value, and the library will add to that variable during processing. This causes the value to wrap around to a very small value, resulting in a buffer much too small to hold the given data. This vulnerability seems to be under active exploitation.
We don’t normally see problems with a log file leading to exploitation, but that seems to be
the situation with the
Below
daemon
. The service runs as root, and sets the logfile to be world readable. Make that logfile a symlink to some important file, and when the service starts, it overwrites the target file’s permissions.
Microsoft’s Patch Tuesday includes
a whopping six 0-day exploits getting fixed this month
. Several of these are filesystem problems, and at least one is an NTFS vulnerability that can be triggered simply by plugging in a USB drive.
The
ruby-saml
library had a weird quirk:
it used two different XML parsers while doing signature validations
. That never seems to go well, and this is not any different. It was possible to pack two different signatures into a single XML document, and the two different parsers would each see the file quite differently. The result was that any valid signature could be hijacked to attest as any other user. Not good. An initial fix has already landed, with a future release dropping one of the XML parsers and doing a general security hardening pass. | 9 | 8 | [
{
"comment_id": "8108993",
"author": "I Alone Possess The Truth",
"timestamp": "2025-03-14T15:29:22",
"content": "“The “backdoor” that was discovered was this set of undocumented vendor-specific commands.” As opposed to …You can’t tell the reader what C2I or a Gerber is in the text but let’s have a... | 1,760,371,607.752974 | ||
https://hackaday.com/2025/03/14/clockworkpi-unveils-new-picocalc-handheld/ | ClockworkPi Unveils New PicoCalc Handheld | Tom Nardi | [
"handhelds hacks",
"Microcontrollers",
"Raspberry Pi"
] | [
"clockworkpi",
"Raspberry Pi Pico",
"Scientific Calculator"
] | Do you like scientific calculators? Don’t bother answering that question, you’re reading Hackaday so we already know the answer. We also know you’re a fan of building things yourself and open source, which makes us fairly sure you’ll be just as interested in the
recently announced ClockworkPi PicoCalc
as we are.
On the surface, it looks like a chunky scientific calculator, though on further inspection you’ll note it comes equipped with a QWERTY keyboard. But open up the case and what you’ve really got is an elaborate carrier board for the Raspberry Pi Pico. The PicoCalc supports all variants of the microcontroller, but realistically we can’t think of any reason that you wouldn’t just use the latest version.
With the MCU connected, you’ll have access to the PicoCalc’s 320×320 4-inch IPS screen, backlit I2C-connected keyboard, SD card slot, 8 MB PSRAM, and dual PWM speakers. Power is provided by a pair of 18650 cells (which you’ll need to supply on your own), and the board has the necessary circuitry to charge them up over USB-C.
Everything is housed in an injection molded case, but the project page says all the necessary CAD files will be eventually be released under the GPL v3 so you can 3D print or CNC your own enclosure. For now though, the only thing of note that seems to be in the
PicoCalc GitHub repository
is a PCB schematic.
The software side of things is a little less clear. The page mentions a BASIC interpreter, MP3 playback, and support for various programming languages, but we get the impression that’s just a list of stuff you can run on the Pi Pico. There are a few images that clearly show the PicoCalc actually being used as a calculator however, so there may be an official firmware yet to be revealed.
The PicoCalc kit is on sale now, and will set you back $75 USD — which actually includes a first-generation Pi Pico, on the off chance that you don’t already have a few laying around.
We’ve been impressed with the previous offerings from ClockworkPi
, so assuming this new kit maintains that same build quality, it seems like a fair enough price. | 33 | 18 | [
{
"comment_id": "8108904",
"author": "Clancydaenlightened",
"timestamp": "2025-03-14T11:16:20",
"content": "Meanwhile I was running android gingerbread on my ti nspire cxGBA, NES, and SNES emulators tooIt Even has a wifi dongle you can get and USB, with color display",
"parent_id": null,
"de... | 1,760,371,607.857475 | ||
https://hackaday.com/2025/03/14/the-trials-and-tribulations-of-building-a-pasta-display/ | The Trials And Tribulations Of Building A Pasta Display | Tom Nardi | [
"hardware"
] | [
"28BYJ-48",
"analog display",
"pasta"
] | We love unique displays here at Hackaday. If you can figure out how to show information on some weird object, we’re all about it. So when
[Julius Curt] wrote in to share his work on the Pasta Analog Display
, we were hooked from the subject line.
But in reading his account, it ended up being even better than we hoped for. Because it turns out, getting pasta to behave properly in an electromechanical device is trickier than you might think. Oh sure, as [Julius] points out, those ridges on the side of penne might make them
look
like gears — but after spending the time and effort to build a particularly slick 3D printed frame to actually use them as such, it turns out they just won’t cooperate. You’d think the pasta makers of the world would have some respect for mechanical tolerances, but unfortunately not.
This version of the pasta display didn’t work, but we love the design.
So if [Julius] couldn’t use the natural shape of the penne to get them to rotate, what was the alternative? First, he switched to the far larger cannelloni. Their increased internal volume, most commonly used to hold spinach and ricotta, has in this case been stuffed with a 3D printed armature. Thus each cannelloni is physically attached to a gear, which means when one of them is rotated by a 28BYJ-48 stepper motor, the rest follow.
All that’s left is to apply some artwork to the pasta (again, easier said than done), and rotate them into position. Depending on how much you can cram onto each cannelloni, the display can be rotated to show several different messages. In the video below, [Julius] shows off three distinct images rendered at the push of a button.
If you get hungry while trying to turn pasta into a workable display medium, you can always cook and eat some of your building materials. Luckily, a couple years ago
Barilla released the design for an open source device
to help you cook their pasta more efficiently. | 14 | 6 | [
{
"comment_id": "8108894",
"author": "Greg Woods",
"timestamp": "2025-03-14T10:36:04",
"content": "I wish I had this much time on my hands!",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8108948",
"author": "Joshua",
"timestamp": "2025-03-14T... | 1,760,371,607.933739 | ||
https://hackaday.com/2025/03/13/the-mysterious-and-important-work-of-prop-design-on-severance/ | The Mysterious And Important Work Of Prop Design OnSeverance | Dan Maloney | [
"Misc Hacks"
] | [
"ESP-32",
"meter",
"Nagra",
"prop",
"servo",
"Severance"
] | Have you seen
Severance
? Chances are good that you have; the TV series has become wildly popular in its second season, to the point where the fandom’s dedication is difficult to distinguish from the in-universe cult of [Kier]. Part of the show’s appeal comes from its overall aesthetic, which is captured in
this description of the building of one of the show’s props
.
A detailed recap of the show is impossible, but for the uninitiated, a mega-corporation called Lumon has developed a chip that certain workers have implanted in their brains to sever their personalities and memories into work and non-work halves. The working “Innies” have no memory of what their “Outies” do when they aren’t at work, which sounds a lot better than it actually ends up being. It’s as weird as it sounds, and then some.
The prop featured here is the “WoeMeter” from episode seven of season two, used to quantify the amount of woe in a severed worker — told you it was weird. The prop was built by design house [make3] on a short timeline and after seeing only some sketches and rough renders from the production designers, and had to echo the not-quite-midcentury modern look of the whole series. The builders took inspiration from, among
other things
, a classic Nagra tape recorder, going so far as to harvest its knobs and switches to use in the build. The controls are all functional and laid out in a sensible way, allowing the actors to use the device in a convincing way. For visual feedback, the prop has two servo-operated meters and a string of seven-segment LED displays, all controlled by an ESP-32 mounted to a custom PCB. Adding the Lumon logo to the silkscreen was a nice touch.
The prop maker’s art is fascinating, and the ability to let your imagination run wild while making something that looks good and works for the production has got to be a blast. [make3] really nailed it with this one.
Thanks to [Aaron’s Outie] for the tip. | 28 | 11 | [
{
"comment_id": "8108838",
"author": "DavidO",
"timestamp": "2025-03-14T06:46:27",
"content": "Beautiful prop! And great example what can be done with just a few parts!!Just a tech one – the needles are steered by stepper motors, not servos. Looks like small car dash gauge steppers … aaand based on ... | 1,760,371,607.995867 | ||
https://hackaday.com/2025/03/13/tracking-deep-sky-objects/ | Tracking Deep-Sky Objects | Bryan Cockfield | [
"Software Hacks"
] | [
"astronomy",
"astrophotography",
"camera",
"deep sky object",
"dso",
"NoVA",
"simbad",
"telescope",
"tracker"
] | Astrophotography, and astronomy in general, takes some fairly specialized tools and a high amount of precision. Setting up the equipment can also take a lot of time, especially for amateurs traveling to various locations with their equipment, so anything that can reduce the amount of time spent looking for objects and increasing the amount of time looking at them is a welcome addition, especially since nights where conditions are ideal for these activities can be rare. [Anton] developed
this real-time tracking tool for deep sky objects (DSOs)
to keep tabs on most of the interesting things out there a telescope can be pointed at.
[Anton] calls his tool the Nova DSO Altitude Tracker and gets its information from
SIMBAD
, updating every minute for a given location on the planet. With that location data, the program calculates altitude and azimuth for various objects and also helps the user keep track of other important variables like moon illumination and angle above the horizon. It also allows the user to highlight specific objects of interest, making sure they are front and center throughout the session. Each DSO can be selected from a list to display detailed information about it such as its path, time visible in the sky, and other properties.
To get the program running, essentially all that’s required is a computer capable of running Python and a display of some sort. From there it provides a quick view of the best objects to point one’s telescope or camera at without any guesswork. With all of the code available it shouldn’t be too much of a leap to do other things with the underlying software, either, such as tying it into a tracker of some sort like
this DIY telescope tracking device
we featured a while back. | 2 | 2 | [
{
"comment_id": "8108841",
"author": "Joshua",
"timestamp": "2025-03-14T07:06:42",
"content": "This reminds me of using SkyMap on a 286 with 4MB of RAM running Windows 3.1!Or SkyGlobe 3.6 on DOS (with S parameter for Super VGA)..It was so fun watching out for interesting celestial bodies.Especially ... | 1,760,371,608.085146 | ||
https://hackaday.com/2025/03/13/a-decade-resistance-box-from-pcbs/ | A Decade Resistance Box From PCBs | Jenny List | [
"PCB Hacks",
"Tool Hacks"
] | [
"gerbers",
"pcb art",
"resistance box"
] | One of those useful things to have around on your bench is a decade resistance box, essentially a dial-a-resistance instrument. They used to be quite expensive in line with the cost of close-tolerance resistors, but the prices have come down and it’s within reach to build your own. Electronic design consultancy Dekimo have a nice design for one made from a series of PCBs which they normally give out at trade fairs, but now
they’ve released the files for download
.
It’s released as Gerbers and BOM with a pick-and-place file only,
and there’s no licence so it’s free-as-in-beer
[Editor’s note: the license has been updated to CC-BY-SA], but that should be enough if you fancy a go. Our Gerber viewer is playing up so we’re not entirely sure how reliable using PCBs as wafer switches will be long-term, but since the pictures are all ENIG boards we’d guess the gold plating will be much better than the HASL on all those cheap multimeters.
We like this as a conference giveaway, being used to badges it’s refreshing to see a passive take on a PCB artwork. Meanwhile
this isn’t the first resistance box we’ve seen with unconventional switches
. | 18 | 7 | [
{
"comment_id": "8108529",
"author": "Christopher Hoover",
"timestamp": "2025-03-13T08:34:31",
"content": "No license means no license.",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8108534",
"author": "jpa",
"timestamp": "2025-03-13T09:03:5... | 1,760,371,608.05116 | ||
https://hackaday.com/2025/03/12/meshtastic-adds-wireless-connectivity-to-possum-trap/ | Meshtastic Adds Wireless Connectivity To Possum Trap | Bryan Cockfield | [
"Radio Hacks"
] | [
"3.5mm audio",
"animal",
"live trap",
"Meshtastic",
"possum",
"trap"
] | Perhaps every gardener to attempt to grow a tomato, lettuce, or bean has had to contend with animals trying to enjoy the food before the gardener themselves can, whether it’s a groundhog, rabbit, mouse, crow, or even iguana. There are numerous ways to discourage these mischievous animals from foraging the garden beds including traps, but these devices have their downsides as well. False alarms can be a problem as well as trapping animals that will be overly aggravated to be inside the trap (like skunks) and while the latter problem can’t easily be solved by technology,
the former can with the help of Meshtastic
.
[Norman Jester]’s problem was an errant possum, but these nocturnal animals generally come out while humans are asleep, and other nighttime animals like rats can activate the trap and then escape. To help with this, a Meshtastic node was added to the San Diego mesh using a 3.5mm audio jack as a detector. When the trap is activated, the closing door yanks a plug out of the jack, alerting the node that the trap has been closed. If it’s a false alarm the trap can be easily and quickly reset, and if a possum has found its way in then it can be transported to a more suitable home the next day.
It’s worth noting that American possums (distinct from the
Australian animals
of the same name)
are an often-misunderstood animal that generally do more good than harm
. They help to control Lyme disease, eat a lot of waste that other animals won’t, don’t spread rabies, and don’t cause nearly as much disruption to human life as other animals like feral cats or raccoons. But if one is upsetting a garden or another type of animal is causing a disturbance, this Meshtastic solution does help solve some of the problems with live traps. For smaller animals, though,
take a look at this Arudino-powered trap instead
.
Thanks to [Dadsrcworkbench] for the tip! | 10 | 6 | [
{
"comment_id": "8108506",
"author": "Robert",
"timestamp": "2025-03-13T07:06:17",
"content": "Press mute before playing video.Actually, if you’re looking for technical detail, don’t press play. The whole video seems to be possum, por…, well, possum footage and not really hackaday-worthy details on ... | 1,760,371,609.01589 | ||
https://hackaday.com/2025/03/12/a-fast-rewind-to-the-era-of-tapesponding/ | A Fast Rewind To The Era Of Tapesponding | Heidi Ulrich | [
"classic hacks",
"home entertainment hacks",
"Radio Hacks"
] | [
"cassette",
"communication",
"long distance",
"magnetic tape",
"reel",
"social",
"tape",
"tape sponding",
"tapes",
"tapesponding"
] | Imagine a time before Discord servers and cheap long-distance calls. Back in the 1950s, a curious and crafty group of enthusiasts invented their own global social network: on reels of magnetic tape. They called it
tapesponding
(short for tape corresponding), and it was a booming hobby for thousands of radio hams, tinkerers, and audio geeks. Here’s
the original video on this analog marvel
.
These folks weren’t just swapping mixtapes. They crafted personal audio letters, beamed across the globe on 3-inch reels. DIY clubs emerged everywhere: World Tape Pals (Texas-based, naturally) clocked 5,000 members from “every Free Nation” – which frames it in a world in terms of East vs. West. Some groups even pooled funds to buy shared tape decks in poorer regions – pure hacker spirit. The tech behind it: Speeds of 3¾ IPS, half-track mono, round-robin reels, and rigorous trust networks to avoid ghosters. Honestly, it makes IRC net ops look soft. Tapesponding wasn’t just for chatty types. It fostered deep friendships, even marriages. It was social engineering before that term was coined. The video is below the break.
What are your thoughts on this nostalgic way of long-distance communication? The warm whirring of a spinning tape reel? The waiting time before your echo is returned? Or are have you skipped
all the analog mechanics
and shouted out into
the LoRaWAN void
long ago? | 5 | 3 | [
{
"comment_id": "8108489",
"author": "echodelta",
"timestamp": "2025-03-13T03:12:26",
"content": "I remember buying 3 inch reels that came in a cassette shaped soft plastic clam shell box, that size made it postal friendly and a label for this purpose was on it. I knew 2 who sent tapes during the Na... | 1,760,371,608.503363 | ||
https://hackaday.com/2025/03/12/eprom-based-enigma-machine/ | EPROM-based Enigma Machine | Bryan Cockfield | [
"classic hacks",
"computer hacks"
] | [
"bombe",
"Cipher",
"colossus",
"eeprom",
"encryption",
"enigma",
"WW2"
] | The Enigma machine is perhaps one of the most legendary devices to come out of World War II. The Germans used the ingenious cryptographic device to hide their communications from the Allies, who in turn spent an incredible amount of time and energy in finding a way to break it. While the original Enigma was a complicated electromechanical contraption,
[DrMattRegan] recently set out to show how its operation can be replicated with an EPROM
.
The German Enigma machine was, for the time, an extremely robust way of coding messages. Earlier versions proved somewhat easy to crack, but subsequent machines added more and more complexity rendering them almost impenetrable. The basis of the system was a set of rotors which encrypted each typed letter to a different one based on the settings and then advanced one place in their rotation, ensuring each letter was encrypted differently than the last. Essentially this is a
finite-state machine
, something perfectly suited for an EPROM. With all of the possible combinations programmed in advance, an initial rotor setting can be inputted, and then each key press is sent through the Enigma emulator which encrypts the letter, virtually advances the rotors, and then moves to the next letter with each clock cycle.
[DrMattRegan]’s video, also linked below, goes into much more historical and technical detail on how these machines worked, as well as some background on the British bombe, an electromechanical device used for decoding encrypted German messages.
The first programmable, electronic, digital computer called Colossus
was also developed to break encrypted Enigma messages as well, demonstrating yet another technology that came to the forefront during WWII.
Thanks to [Clint] for the tip! | 5 | 3 | [
{
"comment_id": "8108448",
"author": "Antron Argaiv",
"timestamp": "2025-03-12T23:36:22",
"content": "COLOSSUS was built to break the Lorenz teleprinter cipher, not the Enigma.https://en.m.wikipedia.org/wiki/Colossus_computer",
"parent_id": null,
"depth": 1,
"replies": [
{
... | 1,760,371,608.463791 | ||
https://hackaday.com/2025/03/12/floss-weekly-episode-824-gratuitous-navel-gazing/ | FLOSS Weekly Episode 824: Gratuitous Navel Gazing | Jonathan Bennett | [
"Hackaday Columns",
"Podcasts"
] | [
"FLOSS Weekly",
"Personal AI",
"scale"
] | This week,
Jonathan Bennett
chats with
Doc Searls
about SCaLE and Personal AI! What’s the vision of an AI that consumers run themselves, what form factor might that take, and how do we get there?
https://www.kwaai.ai/
https://blog.cryptographyengineering.com/2025/02/23/three-questions-about-apple-encryption-and-the-u-k/
Did you know you can watch the live recording of the show right on
our YouTube Channel
? Have someone you’d like us to interview? Let us know, or contact the guest and have them contact us!
Take a look at the schedule here
.
Direct Download
in DRM-free MP3.
If you’d rather read along,
here’s the transcript for this week’s episode
.
Places to follow the FLOSS Weekly Podcast:
Spotify
RSS
Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)
Licensed under
Creative Commons: By Attribution 4.0 License | 2 | 2 | [
{
"comment_id": "8108426",
"author": "Ostracus",
"timestamp": "2025-03-12T21:22:32",
"content": "I’ve been thinking part of a NAS might be a good idea. Problem most commercial units are kind of underpowered.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "81086... | 1,760,371,608.285453 | ||
https://hackaday.com/2025/03/12/flyingcam-is-sweet-diy-webcam-on-a-stick/ | FlyingCam Is A Sweet DIY Webcam On A Stick | Elliot Williams | [
"classic hacks"
] | [
"ESP32",
"ESP32 camera",
"ikea"
] | Imagine you want to monitor a pot on the stove to see if it’s boiling over for just a few minutes, but you don’t want to have a dedicated permanent IP webcam solution in your kitchen.
[Sebastian Duell]’s FlyingCam
hijacks an IKEA lamp gooseneck to become something you never knew you needed: a wireless camera for short-term random remote observation. It’s a beautiful combination of 3D printing and commercial device re-use, and when paired with his DIY wireless screen, it’s a complete solution.
The guts of this project aren’t critical, or expensive. It’s built around one of those ESP32 single-board webcams, with an added fan, battery pack, antenna, and a power switch. You turn it on, and the AP in the ESP32 fires up, or optionally connects to your network. Point the camera at your target and you’re set, at least if you want to sit by your computer. But [Sebastian] also designed a nice simple remote screen, so you can keep tabs on your spaghetti wherever you roam around the house.
We love the attention to keeping the design simple here, both in form and in function. It’s a one-task device, so it’s important that it be extremely easy to use, and it’s hard to beat just pointing the thing and turning on a switch. And it doesn’t hurt that it’s good looking to boot.
IKEA stuff is cheap and cheerful, but often it’s missing just that one functionality that we want.
What good is an air-quality sensor without MQTT logging capability
, for instance?
Or a standing desk that can’t remember set heights
? Get hacking! | 5 | 4 | [
{
"comment_id": "8108372",
"author": "AAMACO",
"timestamp": "2025-03-12T17:56:33",
"content": "Sweet, now I know what I’m going to do with my kids old baby monitor once they’re old enough. Plus, it doesn’t require a local network (but I suppose Sebastian’s project could be made networkless too).",
... | 1,760,371,608.3306 | ||
https://hackaday.com/2025/03/12/pixel-watch-3s-loss-of-pulse-detection-the-algorithms-that-tell-someone-is-dying/ | Pixel Watch 3’s Loss Of Pulse Detection: The Algorithms That Tell Someone Is Dying | Maya Posch | [
"Featured",
"Medical Hacks",
"Science",
"Slider"
] | [
"cardiac arrest",
"health monitor"
] | More and more of the ‘smart’ gadgets like watches and phones that we carry around with us these days come with features that we’d not care to ever need. Since these are devices that we strap onto our wrists and generally carry in close proximity to our bodies, they can use their sensors to make an estimation of whether said body is possibly in the process of expiring. This can be due to a severe kinetic event like a car crash, or something more subtle like the cessation of the beating of one’s heart.
There is a fairly new Loss of Pulse Detection (LoPD) feature in Google’s Pixel Watch 3 that
recently got US FDA approval
, allowing it to be made available in the US after previously becoming available in over a dozen European countries following
its announcement in August of 2024
. This opt-in feature regularly polls whether it can detect the user’s pulse. If not found, it cascades down a few steps before calling emergency services.
The pertinent question here is always whether it is truly detecting a crisis event, as nobody wants to regularly apologize for a false alert to the overworked person staffing the 911 or equivalent emergency line. So how do you reliably determine that your smart watch or phone should dial emergencies forthwith?
Budget Medical Devices
One of the amazing things about technological progress is that sensors and processing capabilities that were rather exotic a few decades ago are now being included in just about any smart device you can strap on your wrist. This includes motion sensors, pulse- and oxygen level meters, making these devices in theory capable of acting like ambulatory
cardiac monitors
and similar medical devices that monitor health parameters and respond to emergencies.
While for a long time the gold standard for heart function monitoring over a longer period outside a hospital setting involved a portable electrocardiogram (ECG) recorder, recently wrist-worn monitoring devices based around photoplethysmography (PPG) have proven themselves to be acceptable substitutes. In a
2018 study by Francesco Sartor et al.
in
BMC Sports Science, Medicine and Rehabilitation
the researchers found that the wrist-worn PPG was not as accurate as the ECG-based chest strap monitor, but came close enough to be practical.
Here the difference is such that applications where precision actually matters the chest strap ECG is still the optimal choice, but wrist-worn PPG devices as integrated into many fitness bands and smart watches are an acceptable substitute, such as when monitoring heart rate for signs of atrial fibrillation. A
2022 study by Christopher Ford et al.
in
JACC: Clinical Electrophysiology
examined two smart watches (Apple Watch 4, KardiaBand) for this purpose, finding that their accuracy here was 91% and 87% respectively.
Together with additional sensors like the commonly integrated motion sensor, these devices seem accurate enough to at least determine whether the person wearing them is suffering a cardiac event that requires immediate intervention.
Health Check
The idea of an automatic emergency call isn’t new, with for example the EU making such a system (called
eCall
) mandatory in new cars since 2018. The idea is that when a serious collision is detected, emergency services are contacted and provided with location and sensor data. Google added its Car Crash Detection feature to the Pixel 3 smartphone in 2019, and Apple added
Crash Detection
to its Apple Watch and iPhones in 2022. These use sensor data from gyroscopes, GPS, microphones, and accelerometers to determine whether a crash just occurred.
What users of these devices discovered, however, was that activities such as going on a rollercoaster ride could activate this feature, as well as snowmobile rides, skiing, and similar activities. In response, Apple had to adjust its algorithms on these devices to reduce the number of false positives. Despite this, rescue workers in e.g. Canada are
still reporting
a large number of false positives. One reason cited is that although there’s a time-out before emergency line is called with audible alarm, this can be hard to hear when you’re on a snowmobile.
As it turns out, defining what seems like a pretty clear event to us when you’re limited to just this handful of sensors is much trickier than it seems. After all, what is different between the sensor data from a rollercoaster ride, a car crash, dropping one’s phone or smart watch onto a concrete floor or forgetting said phone on the roof of the car?
In this context, the idea of taking a simple activity like measuring heart rate and pulse, and extrapolating from these that if they cease, an emergency has occurred is fraught with pitfalls as well.
Merging Data
How do you know as a human being that someone has just suffered
cardiac arrest
? You confirm that they don’t have a noticeable carotid pulse, and the reason why you checked is because they clearly collapsed. This is when you’d pull out your phone and dial emergency services. The LoPD feature that Google has introduced has to do effectively exactly these steps, except that it starts from the loss of pulse (LoP) rather than from seeing someone pass out and collapse to the ground.
Thus the tricky part is establishing whether said collapsing has occurred, not whether the pulse has been lost. After all, the user may have simply taken the watch off.
According to Google
, to verify their algorithms they hired stunt actors to simulate LoP using a tourniquet, cutting off blood flow, and simulating falls like a person suffering cardiac arrest would suffer.
On the sensor side they use the heart rate monitor (PPG sensor), which initially uses the green light to check for pulse, but can switch to infrared and red lights when a LoP condition is triggered. Simultaneously the motion sensor data is consulted, with a lack of motion taken as a sign that we’re dealing with a LoPD. This starts an auditory alarm and visual countdown on the screen before emergency services are contacted with an automated message plus the user’s location.
Then they needed to calibrate the response to this merged sensor data with clinical data on cardiological events before trialing the result with said stunt actors and volunteers. An article on this research was also
published in
Nature
(paywalled, but here is a
gift article
), detailing the algorithm and the way they tested its effectiveness. In the paper the authors note one false positive event and subsequent emergency call across 21.67 user-years across two studies, with a sensitivity of 67.23%.
A Matter Of Time
Chain of survival in case of cardiac arrest. (Credit:
European Resuscitation Council
)
In the case of cardiac arrest, time is of the absolute essence. This is also clearly noted in the Google paper on the LoPD feature, who note that ideally there is a witness on-site who can immediately begin CPR or ideally get a nearby automated external defibrillator (
AED
). Unfortunately in most cases of cardiac arrest, this event goes initially unnoticed. The LoPD feature on a smart watch thus would be for cases where nobody is around to notice the emergency and respond to it. Although it isn’t explicitly mentioned, it seems that the watch can also detect whether it’s being worn or not, which should prevent false positives there.
With over half a million US citizens each year suffering cardiac arrest, and over half of these occurring outside of a hospital setting, this could potentially save thousands of lives each year. Following cardiac arrest and in the absence of resuscitation the lack of blood and oxygen being circulated means that within minutes organs begin to suffer the harmful effects, depending on their oxygen requirements. The brain is generally the first to suffer ill effects, which is why the application of CPR is so crucial.
Because of the intense urgency following a major cardiac event like this, the practical use of this LoPD feature will be highly dependent on the location where the emergency occurs. In the case of someone collapsing while alone at home in their city house or apartment, this could conceivably save their life if emergency services can arrive within minutes. Even faster and more useful in less urban settings would probably be having your smart device notify nearby people who can then perform CPR while calling 911 or equivalent.
That said, perhaps the real killer feature that’s missing here is an integrated AED in smartphones since everyone has one of those things on them at all times, or even smart watches that can automatically perform defibrillation while also notifying emergency services. | 63 | 22 | [
{
"comment_id": "8108332",
"author": "jalnl",
"timestamp": "2025-03-12T15:31:20",
"content": "Remind me not to have a cardiac arrest when sitting in a chair…",
"parent_id": null,
"depth": 1,
"replies": [
{
"comment_id": "8108401",
"author": "Joshua",
"timest... | 1,760,371,608.61328 | ||
https://hackaday.com/2025/03/12/some-useful-notes-on-the-6805-ec10-addressable-rgb-led/ | Some Useful Notes On The 6805-EC10 Addressable RGB LED | Dave Rowntree | [
"LED Hacks"
] | [
"1111",
"addressable led",
"KiCAD",
"RGB LED",
"SK6805"
] | LEDs are getting smaller and smaller, and the newest generations of indexable RGB LEDs are even fiddlier to use than their already diminutive predecessors. [Alex Lorman] has
written some notes about the minuscule SK6805-EC10
series of LEDs, which may be helpful to those wanting to learn how to deal with these in a more controlled manner.
Most hardware types will be very familiar with the 5050-sized devices, sold as Neopixels in some circles, which are so-named due to being physically 5.0 mm x 5.0 mm in the horizontal dimensions. Many LEDs are specified by this simple width by depth manner. As for addressable RGB LEDs (although not all addressable LEDs are RGB, there are many weird and wonderful combinations out there!) the next most common standard size down the scale is the 2020, also known as the ‘Dotstar.’ These are small enough to present a real soldering challenge, and getting a good placement result needs some real skills.
[Alex] wanted to use the even smaller EC10 or 1111 devices, which measure a staggering 1.1 mm x 1.1 mm!
Adafruit’s product page
mentions that these are not intended for hand soldering, but we bet you want to try! Anyway, [Alex] has created a KiCAD footprint and a handy test PCB for characterizing and getting used to handling these little suckers, which may help someone on their way. They note that hot air reflow soldering needs low temperature paste (this scribe recommends using MG Chemicals branded T3 Sn
42
Bi
57
Ag
1
paste in this application) and a very low heat to avoid cracking the cases open. Also, a low air flow rate to prevent blowing them all over the desk would also be smart. Perhaps these are more suited to hot plate or a proper convection oven?
As a bonus, [Alex] has previously
worked with the slightly larger SK6805-1515 device
, with some good extra notes around an interesting nonlinearity effect and the required
gamma correction
to get good colour perception. We’ll leave that to you readers to dig into. Happy soldering!
We’ve not yet seen many projects using these 1111 LEDs, but here’s
one we dug up using the larger 1515 unit
. | 9 | 6 | [
{
"comment_id": "8108261",
"author": "tyethgundry",
"timestamp": "2025-03-12T11:50:43",
"content": "Neopixels are WS2812 compatible RGB LEDs with the 3wire strands [4pin data-in out vcc gnd], running at 400/800kHz signal. Size is irrelevant.Dotstars are the APA102 compatible 4wire strands [6pin cloc... | 1,760,371,608.661438 | ||
https://hackaday.com/2025/03/12/i2c-sniffing-comes-to-the-bus-pirate-5/ | I2C Sniffing Comes To The Bus Pirate 5 | Tom Nardi | [
"Tool Hacks"
] | [
"Bus Pirate 5",
"i2c",
"reverse engineering",
"sniffer"
] | While the Bus Pirate 5 is an impressive piece of hardware, the software is arguably where the project really shines. Creator [Ian Lesnet] and several members of the community are constantly working to add new features and capabilities to the hardware hacking multi-tool, to the point that if your firmware is more than a few days old there’s an excellent chance there’s a fresher build available for you to try out.
One of the
biggest additions from the last week or so of development
has been the I2C sniffer — a valuable tool for troubleshooting or reverse engineering devices using the popular communications protocol. [Ian] has posted a
brief demo video of it in action
.
It’s actually a capability that was available in the “classic” versions of the Bus Pirate, but rather than porting the feature over from the old firmware, [Ian] decided to fold the MIT licensed
pico_i2c_sniffer from [Juan Schiavoni]
into the new codebase. Thanks to the RP2040’s PIO, the sniffer works at up to 500 kHz, significantly outperforming its predecessor.
Admittedly, I2C sniffing isn’t anything you couldn’t do with a cheap logic analyzer. But that means dealing with captures and making sure the protocol decoder is setup properly, among other bits of software tedium. In comparison, once you start the sniffer program on the Bus Pirate 5, I2C data will be dumped out to the terminal in real-time for as long as you care to see it. For reverse engineering, it’s also very easy to move quickly from sniffing I2C packets to replaying or modifying them within the Bus Pirate’s interface.
If you already have a Bus Pirate 5, all you need to do is
flash the latest firmware from the automated build system
, and get sniffing. On the fence about picking one up? Perhaps our
hands-on review will help change your mind
. | 6 | 4 | [
{
"comment_id": "8108215",
"author": "davedarko",
"timestamp": "2025-03-12T08:19:12",
"content": "That’s nice! I stumbled over Juan’s repository when I was looking into I2C sniffing with the RP2040.",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8108425",
... | 1,760,371,608.71081 | ||
https://hackaday.com/2025/03/11/classy-paper-tape-reader-complements-homebrew-retrocomputer/ | Classy Paper Tape Reader Complements Homebrew Retrocomputer | Dan Maloney | [
"Retrocomputing"
] | [
"laser cutter",
"paper tape",
"tape storage"
] | If you were one of the earliest of early adopters in the home computing revolution, you might have had to settle for paper tape mass storage. It was slow, it was bulky, but it was what you had, and that gave it a certain charm that’s hard to resist. And that charm is what [Joshua Coleman] captures with
this DIY paper tape reader build
.
If the overall style of this project looks familiar, it’s because it was meant to echo the design themes from [Joshua]’s
Coleman Z-80
modular computer. The electronics of the reader are based on
[David Hansel]’s take on a paper tape reader
, which in turn was meant to complement
his Altair 8080 simulator
— it’s retrocomputers all the way down! [Joshua]’s build has a few bells and whistles to set it apart, though, including an adjustable read head, parametric 3D-printed reels, and a panel mounted ammeter, just because. He also set it up to be a sort of keyboard wedge thanks to an internal relay that bypasses the reader unless it’s actually playing back a tape. Playback speed is pretty fast; see the video below for details.
So far, writing the tapes is an offline process. [Joshua] uses a Python program to convert ASCII to an SVG file and uses a laser cutter to burn holes in lengths of paper, which are then connected together to form a longer tape. A logical next step might be to build a feeder that moves a paper tape across the bed of the laser cutter in sync with the conversion program, to create continuous paper tapes. Or, there’s always the old-school route of solenoid-powered punch and die. We’d be thrilled with either. | 26 | 9 | [
{
"comment_id": "8108161",
"author": "Cody",
"timestamp": "2025-03-12T05:27:25",
"content": "Now someone just needs to design a high speed paper tape punch so it has something to read. Laser cutting the tape is way slower than the already slow punch on a teletype.",
"parent_id": null,
"depth... | 1,760,371,608.771857 | ||
https://hackaday.com/2025/03/11/lies-damned-lies-and-igbt-datasheets/ | Lies, Damned Lies, And IGBT Datasheets | Jenny List | [
"Parts"
] | [
"datasheet",
"igbt",
"specifications"
] | We have all seen optimistic claims for electronic products that fail to match the reality, and [Electronic Wizard]
is following one up in a recent video
. Can a relatively small IGBT really switch 200 A as claimed by a dubious seller? Off to the datasheet to find out!
The device in question is from Toshiba, and comes in a TO-220 package. This itself makes us pause for a minute, because we suspect the pins on a TO220 would act more like fuses at a steady 200 A.
But in the datasheet, there it is: 200 A. Which would be great, but of course it turns out that this is the instantaneous maximum current for a few microsecond pulse. Even then it’s not finished, because while the continuous current is supposed to he half that, in the datasheet it specifies a junction temperature of 25 °C. The cooling rig required to maintain that with this transistor passing 200 A would we think be a sight to behold, so for all intents and purposes this can’t even switch a continuous 100 A. And the real figure is much less as you’d imagine, but it raises an important point.
We blindly read datasheets and trust them
, but sometimes we should engage brain before releasing the magic smoke. | 44 | 11 | [
{
"comment_id": "8108134",
"author": "0xdeadbeef",
"timestamp": "2025-03-12T02:44:35",
"content": "The cooling rig required to maintain that whitTypo. :)",
"parent_id": null,
"depth": 1,
"replies": []
},
{
"comment_id": "8108135",
"author": "TG",
"timestamp": "2025-03-12... | 1,760,371,609.222721 | ||
https://hackaday.com/2025/03/11/how-to-use-llms-for-programming-tasks/ | How To Use LLMs For Programming Tasks | Donald Papp | [
"Artificial Intelligence",
"how-to",
"Software Development"
] | [
"ai",
"LLM",
"programming",
"tips"
] | [Simon Willison] has put together a list of how, exactly, one goes about
using a large language models (LLM) to help write code
. If you have wondered just what the workflow and techniques look like, give it a read. It’s full of examples, strategies, and useful tips for effectively using AI assistants like ChatGPT, Claude, and others to do useful programming work.
It’s a very practical document, with [Simon] emphasizing realistic expectations and the importance of managing context (both in terms of giving the LLM direction, as well as the
model’s
context in terms of being mindful of how much the LLM can fit in its ‘head’ at once.) It is useful to picture an LLM as a capable and obedient but over-confident programming intern or assistant, albeit one that never gets bored or annoyed. Useful work can be done, but testing is crucial and human oversight simply cannot be automated away.
Even if one has no interest in using LLMs to help in writing production code, there’s still a lot of useful work they can do to speed up the process of software development in general, especially when learning. They can help research options, interactively explore unfamiliar codebases, or prototype ideas quickly. [Simon] provides useful strategies for all these, and more.
If you have wondered how exactly glorified chatbots can meaningfully help with software development, [Simon]’s writeup hopefully gives you some new ideas. And if this is is all leaving you curious about how exactly LLMs work, in the time it takes to enjoy a warm coffee you can learn
how they do what they do, no math required
. | 60 | 15 | [
{
"comment_id": "8108103",
"author": "Joshua",
"timestamp": "2025-03-11T23:38:29",
"content": "Beware, the problem might be the following:These “chatbots” do take information from reliable human sources, such as coding forums.But if less and less human coders remain, the quality of the imformation s... | 1,760,371,608.962469 |
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