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H: Proper behavior for USB and +5V
I have a batch of Sanguino 1.3a RepRap boards, with the following "bug" listed:
The USB 5V VBUS is connected to the output of the 5V regulator. This is bad for the regulator and bad for the PC. Some users report the regulator getting very hot (because it is trying to power the PC), ... |
H: Coin Cell Battery for Arduino/Microcontroller
Excuse the lack of electrical engineering knowledge but I have an Arduino Uno microcontroller that I want to power with a coin cell battery.
The project will have 6 LED lights that will flash for a few seconds every few hours.
My question is, what sort of coin cell batt... |
H: How to hack a body scale to be used as digital weight measure
I am looking for help with hacking a typical digital (body) weighing scale to use in a custom application. Is there some internal digital or analog output in body scales to directly get the measured values? How might I go about reading this output?
I t... |
H: Analog Switch Breakdown voltage?
I'm designing a select-able gain circuit using a multiplexer and an inverting amplifier. Here's an example circuit, using a multiplexer.
I've read that if you provide a voltage larger than the supply voltage it can latch-up and/or damage the circuit due to too high of a voltage.
My... |
H: Correct pin naming of BGA and DIL chips
Some ICs have their pins labelled only with numerical values and some use alphanumeric labels. I want to know what is the correct naming term for these cases.
Is it ok to call all the chips with alphanumeric labels BGA (ball grid array)? And for chips with only numeric pin l... |
H: Should I use pull up resistors in this configuration?
I am interfacing a 3.3V FPGA to a 5V DSP. I am using this bidirectional voltage transceiver:
http://www.nxp.com/documents/data_sheet/GTL2000.pdf
In the diagram in page 4 they're using pull up resistors at the high voltage side and they state:
The processor outp... |
H: Reducing cost by eliminating microvias when designing a PCB with buried vias
I'm designing a 4-layer PCB for a very small adapter from a BGA on one side to several discrete SMT connectors on the other. Due to space constraints, I cannot use through holes for some of the interior connections; they must be routed th... |
H: How is oil-filled switchgear possible?
I can't find any definitive description of how oil-filled switchgear uses the oil and manages to keep it from ignition and boiling. For example, the Wikipedia article says
Oil circuit breakers rely upon vaporization of some of the oil to blast a jet of oil through the arc.
w... |
H: Change in PLL settling time as a result of halving charge pump current/doubling loop filter capacitor
I have a PLL that is operating unstably at some temperatures. I have been able to show that reducing the charge pump current from 128uA to 64uA ensures that the PLL will operate stably at the same temperature poin... |
H: How can I tell if a particular multimeter measures AC with RMS or Average
I require a multimeter measuring RMS but unfortunately know little on the subject and am unable to tell which method one uses from it's description.
Its states:
MAX. Voltage between terminals & earth ground: 700V AC rms or 1000V DC
Fuse P... |
H: Controlling an RGB LED color range from an analog temperature sensor (no Arduino, etc.)
I'd like to combine an analog temperature sensor with an RGB LED so that I get a range of colors based on temperature. Low temperature blue, high temperature red, with color fade between them as the temperature changes. For se... |
H: Making a burglar alarm
I am using a passive infrared sensor TMP006 to make a burglar alarm. However I notice that the data returned is not accurate enough. Are there any other ways by which I can improve my accuracy. Or should I use an ldr on which I shine a continous beam of IR light which breaks when the burglar ... |
H: Do two stage common emitter current amplifiers add or multiply?
So I've seen alot of explanations on two stage voltage amplifiers and how how their gains can be multiplied together. My question is when you are using a two stage common emitter amplifier for current amplification, does the current gain from each stag... |
H: how these circuits work?
I have 2 shematics of circuits in order to drive a LED
I want to know how exactly these circuits work and what is the reason of using each components and why we need a dc-dc converter
Tnx very much
the link of the image is
http://www.infineon.com/dgdl/LED+Driving+Concepts+and+Infineon+Basi... |
H: Set top boxes - database of ‘tv programme/channel’
I am currently researching the construction and functionality of set top boxes for services such as Sky + and Freeview.
I need to understand if and how a database structure would be used in terms of the operation of such hardware.
As these devices are accessing l... |
H: Multiplexing, Animation, Bitmap coding on MCU. How to do it right?
I have been recently getting into programming and micro controllers.
I found myself that i don't really know how to do multiplexing, animation, easily displaying pictures on LED display.
I have been looking for some code examples, but most of the a... |
H: How does audio get transmitted from my iPod to speakers?
I need some help understanding a simple concept. I understand that my iPod/any other audio device sends electrical signals to my speakers/headphones.
From my research so far, an analog signal is sent. Now what I need help understanding is that what is the ana... |
H: PCB part naming for LEDs
Usually when I design a PCB, I name the LEDs as LED1, LED2, ... , but now I'm working on a set of boards where I do not have much space for the component names on the silkscreen.
The boards are divided in four functional blocks.
In order to be able to better identify which parts belongs to ... |
H: Price History of FPGA
My goal is to extrapolate (or estimate) the future prices of FPGAs and/or ASICs.
Does anyone know of the price history of FPGAs or ASICs? I am looking for a source of information.
I know that today FPGA's can be categorized into three basic categories (High end, mid range, and low end FPGA)... |
H: Which schematic is better for keypad connection to an MCU?
I have this three keypad connection sketches, all of which i've seen in various application, and some i've also used, but i want to know if there is any advantage of one over the other.
The keypad will be connected directly to DIO pins of a PIC microcontro... |
H: Basic wattage and volt conversion when using solar panel
I have a basic electronic question or two I need to ask.
I want to use a solar panel which delivers 5.2W and is rated for "8V open voltage and 650mA short circuit". If I connect a 5V voltage regulator to lower the volts to 5V, would the amps go up to be 1A af... |
H: Does higher dBi mean further range, for an antenna?
I recently purchased this (ridiculously expensive) Bluetooth module for my Arduino from SparkFun. On the item's page it says that it has been tested at 100 m. I contacted SparkFun for info about their setup and they said to achieve the 100 m range they used this... |
H: Solving input noise
I built a very simple circuit so I could use my Bose headphones in the noisy server room without wasting batteries. I however feel silly that I did not know how noisy USB power was, thus the V(L) power is to noisy for the headphones to function properly.
I'm pretty sure I just need an inductor ... |
H: What does frequency foldback do in a switching regulator?
I'm looking into using the LT3759. One of the features that they advertise is frequency foldback.
Frequency Foldback
When VOUT is very low during start-up or a short-circuit fault on the output, the switching regulator must operate at low duty cycles to m... |
H: Relay current question
For the 16 CH 12V Relay module, does the output currency mean that we could run 5VDC, 12VDC or 24VDC through the relay? What ever current we input will be the output current, correct?
AI: 1) Yes, the relays installed on the module are rated at 30VDC, 10A; so you can use it to drive anything b... |
H: Specific color sensing, is it possible in an economical way, without using camera/image recognition?
While I understand that color sensing with camera and sufficiently powered processor running image histogram logic (or other such algorithms) can determine presence of certain colours fairly reliably.
However, are t... |
H: Magnetic door lock
I'm looking at buying an AEM10010 magnetic door lock (see page 4 of datasheet), but can't figure out how they're driven. The datasheet doesn't say anything about how to connect them, nor does it provide any in-depth technical specs.
I can only assume they have two wires, one for ground and one fo... |
H: Calculating parallel resistance of a rated bulb
I have a bulb rated 110 V, 60 W and is in series with another bulb which is 110 V, 110 W. It's being powered with a 220 V source. Now, what would be the resistance of the resistor to be added in parallel to the first bulb so that each bulb will get the rated power?
T... |
H: Selecting a MOSFET for driving load from logic
I'm looking to drive a magnetic door lock from an Arduino. I've found a question about driving a solenoid from an Arduino, which includes a circuit that looks perfect for this kind of situtation:
What I don't understand is how to select a MOSFET for the job. What prop... |
H: Does this photodiode circuit work?
Oli used this circuit
in an answer, and it pops up a lot on Google images too. But does it work? If it does a theoretical explanation will be welcome.
AI: According to this, the photodiode does indeed produce a current even when there is zero volts across it; it's the short circ... |
H: What is the definition of "cathode"?
According to Wikipedia's definition, a cathode is "an electrode through which electric current flows out of a polarized electrical device". However, the direction of current flow is purely an arbitrary convention, and is in fact the opposite direction to which electrons flow in ... |
H: Help finding appropriate AVR device
I am working on a student project and need to find AVR microcontroller that will suit all project requirements. Here's a simple list:
serial communication (UART),
at least two ADC channels,
PDIP package (for easy soldering, I do not have access to expensive equipment nor do I ha... |
H: Diagram validatation for two motors connected with On-Off-On Switch
I want to connect two motors on an On-Off-On switch. On position 1, I want motor 1 to me active, on position 2, I want motor 1 and 2 active.
Here is the diagram I was thinking of implementing
My second question, if this work, what kind of Diode sh... |
H: query about the RAM IC in this picture
Have this ZOOM recorder and it came with 150V power adapter. It got accidently plugged to a 250V and went dead. I opened to see if it can be fixed and found this RAM IC EM638165TS in this condition:
Im just a amateur in this field can't understand if this picture looks normal... |
H: How to calculate current and voltage draw of a single resistor circuit?
If I have a single 270 ohm resistor connected in a circuit to a 3.3V 50mA power supply, how can I measure the voltage and current for the resistor? I'm familiar with Ohm's law V=IR, where V is the voltage differential, but what is the different... |
H: Using a specific LCD with an arduino
I have the following lcd (DisplayTech 128x64 COG STN Y/G) unfortunately after reading the data sheet I still have no idea how to hook this up with an arduino. Could someone either assist in explain how this needs to be hooked up and how you would interface with it once connected... |
H: Designing high-power LED driver with PWM
Update:
Provided I set up the PIC and program it correctly (planning on using this guide to interface it as a USB HID device), would this be a suitable configuration? I'm not entirely certain how I should be deriving values for the passive components outside of the manufact... |
H: Creating a clock multiplier using a PLL
I understand that PLLs can be used to modify the phase of a clock signal for various purposes. I have also heard that PLLs are often used to multiply clocks.
How can a PLL be used to multiply a clock?
AI: The normal method for using PLL to multiply frequency is analogous to ... |
H: Discrepancy between post-Place-and-Route static timing analysis and ISIM simulation results
Overview
I'm implementing a simple Harvard-style CPU using Xilinx ISE version 14.1. I'm using settings compatible with a Digilent Nexys3 board, but for the time being the entire project is performed in simulation only.
I hav... |
H: Eliminating Thermal Isolation Pads in Eagle
When creating a ground plane in Eagle, Eagle automatically creates a thermal isolation for the pad.
My first question is, does this isolation limit the current compared to a pad that is "completely" connected to the plane?
My second question is, is there a way to make ... |
H: Understanding the AVCC pin wiring on ArduinoLeonardo (low-pass filter?)
The Arduino Leonardo has an interesting difference with previous boards: the AVCC pin of the ATMEGA32U4 is connected to +5V through a MH2029-300Y ferrite beads and to GND through a 1uF capacitor.
In ArduinoUno and ArduinoMega2560, this pin was ... |
H: Acer Aspire 7535-5020 battery
I need to replace my Acer Aspire 7535-5020 battery. The original battery has the spec: 10.8V, 4400mAh, 48Wh.
The Acer Website says: "6-cell battery pack"
The Quick guide for my model says:
3.36 kg (7.4 lbs.) with one HDD and 8-cell battery pack
3.25 kg (7.1 lbs.) with one HDD and 6-c... |
H: Does Arduino use step down voltage regulators?
I am designing my first "permanent" Arduino application, and I would like to know if the voltage regulator is linear or step down.
The reason I would like to know is because I am currently powering the prototype with an 11.1V 1300mAh LiPo battery. If it uses a linear ... |
H: Common Analog Signal Frequencies
I'm trying to scope out what frequencies different common analog signals are. The DPScope design specs provides a list of common lower (sub 1 MHz) frequencies (copied below).
audio (20 kHz)
infrared remote control signals (38 kHz)
ultrasound (200 kHz)
servo signals (a few kHz)
bio... |
H: How to indicate breakaway tabs in PCB design?
I'm designing two boards that'll always be used together. I'd like to place them both on a panel and break them apart after manufacturing.
I found a document on PCB CAD Design Guidelines that explains breakaway tabs and lists guidelines for their design.
Board assembli... |
H: I ran into LCD problem
I am using Arduino mega 2560 and LCD with I2C. it is working well powered by USB but not working powered by external wall charger (9vDC). The LCD is on without any character.
Do you know the issue and do I need to adjust the brightness and how?
Thanks!
AI: The link you have provided shows a L... |
H: How to go from GPIO to digital signal?
I'm sitting here with my Raspberry PI and some other equipment that requires digital signal (high/low, enabled/disabled).
But the Pi only has a GPIO so to get it to work I would need a microchip of some sort (guessing)?
I'm fairly new to all this, but like to play around on my... |
H: How can I get extra power for USB 2.0 device?
I have a raspberry pi and a WiFi module, unfortunately I can't get enough power from the raspberry to power up the WiFi module. Can I power up the device if I cut an USB cable, I'm letting the data wires untouched and I connect the power from an external power supply?
A... |
H: R2 Arduino Uno and an R3 Ethernet Shield mismatch
I bought an R3 Ethernet shield for my R2 Arduino Uno, but I noticed that it has a few more pins than my R2 Uno has sockets. Do I need to buy a different shield?
Arduino UNO
Arduino Ethernet Shield
AI: When I take a look at the schematic for R3,
it appears that the ... |
H: Is it okay to keep a mobile phone connected to its charger, 24 hours a day, 7 days a week?
I want to ensure that a mobile phone is always charged, without requiring manual intervention: e.g. disconnecting/reconnecting the charger, switching the charger on/off, et cetera). One idea would be to leave the phone always... |
H: Backup battery tester circuit
I am attempting to read the voltage on a backup battery on an Arduino. To that end, I used the circuit Olin Lathrop offered in answer to this question. I am powering the Arduino with 5V, and the battery is 3 AA cells, so 4.6V or less.
Using the battery checker circuit Olin offered, s... |
H: How do I use a quartz crystal in an oscillator?
How can I get a quartz crystal to make square waves at 4.096MHz? So far I have the 4.096MHz quartz crystal and this schematic I saw:
Where can you find an amplifier with a single input and what voltage should I use?
AI: You can make a Pierce Oscillator similar to th... |
H: Displacement Sensor
I am working on a project where I need to measure lengt of the objects floating on a surface. To perform that kind of sensing I am currently focusing on mouse sensors.
I first tried ADNS 6010; however, 8-bit delta x/y output (as displacement amount registers) of it became so small for the speed... |
H: How do I get this spool to work?
I have this spool (image) and did some testing with a multimeter before I disassembled it. It's working range was [-3.3v,0v,3.3v]. When I tested it by just applying the battery after disassembly nothing happens.
Does this work in other ways then just applying the correct voltage?
... |
H: What does it mean when there is a voltage difference between ground and neutral?
Between ground and hot there's approximately 120V as expected.
I had expected the voltage difference between ground and neutral to be 0v, but instead it's 0.4V. Why would this not be the case? Is it a hazardous condition? How would ... |
H: How does current flow through this Arduino circuit?
I must admit I'm rather ignorant of all things electric, so I got an Arduino with the intent of filling this gap in my education, and also learning more about the physics behind programming and do low-level stuff, but I've not found a proper theoretic introduction... |
H: Why don't my coil work?
I disassembled my old Niko RC car today. Thought I could play around with the parts.
But what I can't seem to understand is the coil. The powersource of the rc car is a 7.2v NiCd 620mAh battery. And as you all see (image 1) I've tried to connect it directly on the coil - nothing happens.
As ... |
H: Buzzer on a computer mainboard
I would like to remove the buzzer on an Intel mainboard, and replace it with an LED with a resistor. Is there a standard voltage that I can assume that comes to the two ends of the buzzer?
Why was a buzzer used in the design of computer mainboards instead of an LED?
Update: My buzz... |
H: Fixing APC UPS buzzing noise
I have an APC UPS and one of the caps - an SIEMENS EPCOS 20uF 150V Capacitor - started making a buzzing noise.
This seems to be a AC, non-electrolytic capacitor and most local stores have it priced at ~$20 + tax.
They look like this:
I also realized that caps of similar rating (20uF 25... |
H: Crystals, Oscillators, and Resonators. What the difference?
I am trying to figure out the difference between crystals, oscillators, and resonators. I'm starting to grasp it but I still have some questions.
From my understanding, an oscillator is built from a crystal and two capacitors. What is a resonator then? ... |
H: Sending a analogue signal?
I have this old Nikko Tiger 2 RC car I've been playing around with. At first I disassembled it and played around with the parts and my parts (motor controller++).
But then I asked myself, can't I use the parts already in there? And put the end of the antenna of the RC car (not the remote ... |
H: Arduino: two more analog input!
i'm dealing with analog sensors. I have an Arduino Lilypad Simple Board with only 4 analog input.
Now, i need two more sensors and i've found on the net this schematics:
But i don't understand if it could add delays on my project because i'm controlling audio-video stuffs and any ki... |
H: Is galvanic isolation of Hi-speed USB impossible?
I have a USB isolator which provides galvanic isolation of a USB device from my PC, but only works for low speed and full speed USB. I can't find any alternative electric isolators which do provide Hi-speed connection; USB fiber extenders, however, are offered with ... |
H: What is the difference between burden resistor and a normal one?
I just came across the word 'Burden Resistor'. Is it any different from a normal resistor?
If it is different, where can I possibly get one? Sparkfun hasn't got one listed. Any help is appreciated. I am trying to build a current sensing circuit.
AI... |
H: I broke my steering coil, where could I get I new one?
I broke this coil:
Does anyone know where I can pick up a similar coil? It was placed in my Nikko RC toy car (Nikko Tiger 2).
AI: Chances are that this was custom made for Nikko, and that it isn't for sale is shops. If you want the same thing you'll have to bu... |
H: Choose the resistence with voltage divider sensor
I'm on voltage dividers circuits for reading some sensors that changes their resistance (force sentive resistor).
With my tester (with input scale set on 200K ohms) I read 23 if sensor is not touched and 65 if the sensor is touched at maximum.
Now, I'm trying to rea... |
H: Which is easier to solder: TSSOP or QFN?
Which package easier to solder on home-brew PCBs:
TSSOP
QFN
I generally use solder paste and hot-air / hot-plate.
AI: For hand soldering I'd go with TSSOP. QFN pretty much requires hot air, whereas you might be able to get away with a soldering iron with a TSSOP. The pit... |
H: UART adapter to... what is this connector's name?
Any idea of what the connector from the right is named?
AI: The left one is called Micro-MaTch™ connector, and it's a board to flat cable
or board-to-board connector. This is a two-part connector, but there are also versions where you solder the flat cable holding... |
H: switching DAC output to multiple inputs
I am currently using a DAC (mcp4922) and want to send the output voltage (0 to 5V) to 1 of many (14) inputs on an Arduino Mega.
I am currently using some VN2222 fets for switching (because I had them laying around) but would like to get something with a higher density. They a... |
H: Clamp / pierce into flex PCB
I'm hacking a pair of active-shutter 3D glasses. Leading to each lens is a flex PCB with 2 traces. I'd like to connect into those traces about 5 mm away from the lenses. How can I go about making a connection into them?
melt the flex PCB to leave just the bare copper?
somehow crimp met... |
H: Standard wire colors
I am fairly new to "electrical" engineering as a hobby/ past time. I have always loved electricity and have made simple circuits since I was a little baby.
I am now working on one of my first arduino projects and I started thinking about what color wires I should use for the different I/O an... |
H: Inverter ICs for (5v DC -> 5v AC) and (9v DC -> 9v AC)
What are some ICs that can turn 5v DC into 5v AC? How about 9v DC into 9v AC?
I'm wiring up the liquid-crystal lenses from active shutter 3D glasses to be electric-powered sunglasses. Depending on the lens model, they need either 5v or 9v to go fully dark.
They... |
H: Are sealed lead acid batteries water-resistant?
I am going on a climbing trip in the Canadian Rockies for 20 days starting this weekend. I am bringing a 12volt 7Ah SLA battery that I am going to use to charge my GPS, iPod, Camera, and Sat Phone.
I ordered this Yuasa battery. Will using this in a wet environment... |
H: Can I charge a 12v sealed lead acid with an old wall-wart (not made for charging)?
Will it hurt the battery? If I left it overnight would I run the risk of "exploding" the battery?
I have a 7Ah SLA battery that I need to charge, but I don't have a charger and I don't want rake out $50 for a charger. Even if I did... |
H: Arduino Analog Input example clarification
First of all I'm total nub in electronics.
Recently I got an Arduino Nano. Now I'm trying to understand why there is no potentiometer nominal at http://arduino.cc/en/Tutorial/ReadAnalogVoltage example and how variation of this nominal would affect Analog input readings.
A... |
H: How are multi-layer PCBs made?
I know how normal PCBs are etched, but every time I grab a magnifying glass and examine the edge of a multi-layer board I'm astounded by the precision that must be required during production. On top of that, some of them have buried vias and other such trickery, which must further com... |
H: Powering 3 LEDs
I have 3 LEDs which I assume are white (they look white, in a blue glass/plastic).
I need to power them, but Im a bit rusty with my electrical knowledge.
I have the following power supplies (all 240v mains input):
Nokia cell phone charger: DC 5V/350mA
ATX 320W PC power supply
Some weird AC conver... |
H: PICKIT 3 and 16F684 in-circuit debugger
I am not sure which other parts (except PIC KIT 3) do I need for in-circuit debugging of PIC 16F684...
Do I need additional ICD header?
What about RJ-11 adapter/cable to connect PICKIT and header? Do I need one or is it included with header?
Is it possible to use in-circuit d... |
H: How to configure the analog port in PIC18F?
How to configure the analog port of PIC18F452 to read analog values? They need to change their status while running the program.
AI: Check the PIC18F452 datasheet (google it). It will say how to set ADCON0 and ADCON1 registers in order to set portA pins to work as either ... |
H: How is a transformer working at 10's of MHz designed?
In this answer a switching power supply using a transformer operating at 10's of MHz range to reduce size is mentioned.
How would such transformer be designed? Would it still have a plain old design with a core and windings, just smaller, or would it have some a... |
H: Powering LED with 9V battery
I want to take an LED and power it with a 9V battery. I just don't seem able to get the math right.
Taking an average 9V battery and a 10mm LED, what kind of resistor would I need and how do I know for how long the LED will run on the battery?
Also, can infrared LEDs be "seen" (using a ... |
H: How can I make a thermostat?
I would like to make a threshold-temperature on-off switch (a.k.a. a thermostat). Short of buying a commercial sensor like an LM335Z (I know that it's super cheap) and figuring out how to use the output, I thought that it could be a fairly simple task to design something that would turn... |
H: Programmable power supply
I have been assigned to design a kind of programmable power supply. Can't decide on a way to make it. Need help with this.
This is a high level block diagram of the required system:
How it works (How it should work)
The system will be given 0 to 10 Volt variable input, which decide outpu... |
H: WiFI signal level in dBm
I have a outdoor WiFi connection, each module has a 5dBi antenna, today I extended with a 16dBi directional external antenna. before it was -65dBm the received signal level now it's -83dBm, I'm a bit confused I waited to increase the value, like -30dBm? Is it a better value?
AI: No. -83 in ... |
H: HOA0901 Wheel Encoder Circuit
I am trying to use the wheel encoder mentioned in the circuit but somehow i can't manage to understand why there is a full voltage drop in the IR led and why the resistors are not limiting that voltage drop, considering that in "ohmic" terms my circuit should work.
I would like somebod... |
H: MicroSD flash block size
I'm working on a low-power application with data storage on a microSD card. In the interest of minimizing power consumption, I'm planning to buffer data to RAM before writing, and I suspect that the optimal buffer size would be an integer multiple of the flash block size in the SD card, as ... |
H: Mylar Paste Stencils - Paste Mask File Conversion
I want to cut some cheap mylar stencils from mylar for quickly assembling some fine pitch SMT designs. I have access to a laser cutter for this purpose. The laser cutter accepts various file types... unfortunately g-code or RS274x is not one of them. Does anybody ha... |
H: What is the simplest sound generating circuit?
I'm relatively new to electronics, and have no formal training other that what I picked up through my electrical engineer father. I solder well, can read schematics, have assembled kit projects with a rough understanding of how all the parts work, and know basic electr... |
H: High-side current monitor to measure microamps
I am trying to sense very low current (50 - 200 μA) on the high side of a circuit, and was considering LTC6102HV for the job since it can be "floated" to 105 V.
My problem, however, is that my circuit is not floated to +105 V but to -105 V and the current does not flo... |
H: Arduino SPI limit
Is there a limit to how many slaves you can control with a Arduino board using the SPI bus as long as you do not run out of pins?
Uno, for example, has 14 digital I/Os. So theoretically, I could have 11 slaves if I wanted to since MISO, MOSI and SCLK will be shared and there would be 11 different... |
H: How to use Altium Buses?
I am new at Altium, I am trying to connect 8 wires but using a bus. I have read about this in Altium's web page but I doesn't explain too much about how to connect buses on the way I need. I want to connect in this way:
I know pin count doesn't match on both sides but that is my idea. I wo... |
H: Why do batteries not last as long in a cold environment?
I know that batteries don't lase as long when they are used in a cold environment, but why is that?
For normal conductors resistance decreases as temperature goes down, so shouldn't the internal resistance of a battery go down as well, making it more efficien... |
H: Using electric motor to adjust blinds?
So I'm trying to do some insane home DIY with my room blinds. I'm trying to make them adjust (go up and down) automatically.
Now for this, obviously, I will need a motor.
The blinds I'm working with don't require much strength to pull down, but a fair bit to pull them up (usi... |
H: What's the max discharge (in "C") of a Pb-acid and LiFePO4 (lithium iron phosphate)?
I know that lead acid batteries can handle massive loads, and they are even used to power houses with solar panels, but what is the maximum safe discharge for one of these?
I've done some Googling but I can't seem to find a number.... |
H: A quick question about TFT LCD
Can I use this 1.8" TFT LCD to make it show graphic? Or all the TFT LCD can display graphic?
AI: Yes, you can draw graphics on this display.
You can draw graphics on any display that is (individually controllable) pixel based, i.e. it mentions a resolution, something like 128 x 160 ... |
H: Use sheet entries on Altium
I am trying to make a sheet entry to use ports to connect devices in different sheets as explained in this image:
But I am getting an error from Altium saying:
Sheet Entry RB[0...7]
Warning: Nets whit multiple names
Error: Nets whit possible connection problems
Of course, nets are not ... |
H: Transformer winding ratio vs actual winding count
Output voltage of transformer depends on ratio of winding count on primary and secondary coils, but is there an impact on transformer performance by actual winding count?
Say, i want to have 1:2 ratio, i could wind 10:20 or 100:200 windings.
In general, more winding... |
H: What wattage should a headphone amp be?
I was at a local surplus store today and I got two LM386N ICs. I thought I could make a really simple headphone amp out of these. But I have no idea what the wattage of a normal headphone amp is.
These LM386 are rated 325 mW at 8 Ohm, which should be about 81.25 mW at 32 Oh... |
H: What is "RFIS" tag
I read somewhere about "RFIS" tag. I know what is "RFID" but does something called "RFIS" exist? I tried to search but all suggestions are RFID related. Would be nice if you have any clue share it please.
It could be just a mistake, so just simply it should have been RFID! or maybe this is someth... |
H: CE# pin pulsed low by ARM when configured
I have an STM32F2 that has a "Flexible Static Memory Controller" (FSMC). For some reason, when I configure the Chip Enable (CE#) pin of my PSRAM as a FSMC pin, the STM32 will pull the pin low (by default the pin is pulled high with an external pull-up).
The reason I ask is ... |
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