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H: Loop is executing infinite times I am working with an ATmega32-A microcontroller. Using USART communication, I am displaying data on monitor and am using switch case to select different commands. In one of the commands I have written the following code: case(DATA): init_io(); statusreg = AD7798_8(0x40, 0xFF);...
H: For a lower voltage drop one could use Schottky diodes, but what are the disadvantages of Schottky's? In other words, why don't we always use Schottky diodes if they are so much better? What diode properties do Schottky diodes have that makes them unfit for certain applications? AI: They cost more, have higher reve...
H: Designing Pick-and-Place-friendly CAD library parts I'm working on a PCB design with surface mount components to be manufactured by a PCB assembly shop. I'm using CADSTAR, and I had to populate the library with some components, from scratch. I'm new to this, and I want to make sure I'm defining component outlines a...
H: hierarchy of op-amps choice for class use I saw mentioned in another question that a 741 is one of the worst designs. An LM324 is also pretty low-end. Is there a better low-end operational amplifier for the money? I would just appreciate knowing a hierarchy of people's favorites. Obviously, if I can get LM324 for ...
H: Oscilloscope reading not what I expect I had my first very exciting and successful go at an oscilloscope today. The question which arose at the end of my first experience has to do with the accuracy I was expecting. My microcontroller was programmed to output signals such as a HIGH signal for 80us, LOW for 50us, HI...
H: How can I get this button to be more reliable for my arduino program? I have been working on this program for a simple controller. I have a prototype all wired up and working however the momentary push button is not very reliable. Sometimes it reads and other times it ignors it. Here is my code. /* * Valve Purge C...
H: What is the physical representation of the heap and the stack? I can easily understand how .bss and the code have physical representations in the processor which has a memory bank for the instructions that a program counter can count up and the bss (block starting symbol) is just global data. But then there is the ...
H: Driving a LED with an open drain digital output I need to drive an LED from an STM32F217ZG. So I was thinking about a classic circuit with a BJT. But then I saw that GPIO outputs of the microcontroller are configurable as open drain. Would this circuit work? The LED has a 20mA forward current and a 2V forward vo...
H: How do the lights on stairs work? I remember that there's a very simple circuit diagram that explains how there can be 2 light switches for 1 light and that regardless of which switch you turn 'on/off' the light is toggled on/off. This, as I recall, is the same circuit that is used for the light on a staircase wher...
H: Developing for an FPGA using Impulse C I am considering using Impulse C to write C code that will compile down to HDL for my FPGA. I'm curious as to what experiences people have had with Impulse C, to better understand the advantages and disadvantages, and in what cases it makes the most sense to use Impulse C as o...
H: Should I use a parallel or serial connection? I need to split one power cord from the wall socket to power three 20w lamps. Should I use a parallel, or a serial connection? Follow up question: In which ever case, where can I find some guidelines for how to proceed? AI: As long as the 20W lamps are designed to opera...
H: Will an opening fuse cause an inductive kick, or not? I'm looking at designing a high-current crowbar circuit. We need to blow a 1400A fuse on demand. One question that has arisen is, what about inductive kick? If you short a large capacitor through a fuse, like so: the current in the fuse path may well reach 50kA...
H: Using GPIO in PC I've got a simple project on host device that should drive 2 pins with high logic level (voltage 3.3V, 5V or 12V - doesn't matter) and wait for 2 others pins become driven high level by the peripheral device. Can I implement such host device with a standard PC and what hardware (built-in or extra) ...
H: stepper motor overheating I'm using an Arduino to control[1] 2 stepper motors [2][3] (both obtained from scraped printers and I can't seem to find datasheets for them). First I used a 12V 0.5Amp power supply, that worked for each motor separately (although [3] lacked some torque), but when connecting them together ...
H: Analog to digital conversion I am using an Atmega32-A microcontroller and an AD7798 external ADC. I am able to set the ADC registers and read back ADC values. I have written the following code: statusreg = AD7798_8(0x40, 0xFF); // read STATUS register default value Id = AD7798_8(0x60, 0xFF); ...
H: Can pins (breadboard friendly) be added to non-drilled pads? Some PCBA's have pads along the edge, where I believe some kind of headers could be soldered (or may be not), but don't have the pads drilled. I guess manufacturers save a little cost on drilling, and is not a problem when these are breakout boards used i...
H: (Bad) counting digital pulses with Arduino using interrupts and a 4 pin switch I have to write an Arduino sketch to accomplish some tasks with the number of digital pulses detected by a pin. For this purpose I chose to use interrupts in order not to miss any pulse and perform the rest of the algorithm virtually at ...
H: Automatic Rotating Platform I would like to build a very simple, circular wooden platform that rotates automatically - no stopping. The torque is not very important, as it doesn't need to support much weight. As far as rpm, not too fast, but not incredibly slow - about the pace of a fast escalator? That's the on...
H: Electronically controlled pneumatic lift, or something similar Need to be able to firmly lift about 110Lbs (~50Kgs) weight, through a distance of upto 12 inches. The weight can be considered to be a flat & square wooden board, hinged to a flat platform, with the lifting action applied to the free end, s.t. the wood...
H: Current measurement in component level of an embedded system I have an embedded system with a MCU, GPS module, GSM module and TI module. The project is largely depend on the total battery consumption. In order to characterize battery consumption, I have to measure current with respect to each module from the embedd...
H: Multiplex Seven Segment Display Fast enough to make Solid I have been trying to multiplex a 4 digit seven segment display on my FPGA board but have been running into not being to get it fast enough so it looks solid to the human eye. You can see an example of the speed here: http://youtu.be/geTgZcHrXTc How do multi...
H: clarification about amdahl's law A system is designed as a cascade of of 4 subsystems, each contributing the same amount of time to the average service time of the system. If we wish to increase the speed of the system by a factor of 2 by reducing the service time of each subsystem equally, how much speedup should...
H: Ethernet (100 Mb/s) through relays I'm trying to transmit Ethernet through relays. I'm using relays because I need them to switch to another signal path, and I'm specifically going to use relays and not other switching devices so that things are fail-safe and still provide a path when my device controlling the rela...
H: Replacing (and perhaps upgrading) bad capacitors within a speaker system? A few months ago the volume of the left speaker of my pair of low-cost audio monitors began slowly diminishing. Every day it seemed to lose a fraction of it's normal operating volume until the speaker became nearly completely silent. Since I ...
H: Basic ac circuit analysis When are we going to append the "j" term when analyzing ac circuits. When i say j term, im pertaining to opposition to current/impedance. In the image below, notice that Xl is not written as jXl. When are we going to use the j term and when are we not going to use it? AI: "notice that Xl i...
H: Any reason power supplies always use single sided PCB's? I am designing a PCB that has an onboard power supply switching module which requires filtering and protection on the input and output side. Its going to be a double sided PCB but I was wondering if the power supply section should be kept to a single layer. J...
H: How to test if the voltage in a circuit is a certain amount I recently found out that memory is stored in a computer with lots of capacitors that hold 0 or 5V. I presume this is how binary would work (so 5V is 1 and 0V is 0). How would I (say) turn on a lightbulb if the voltage is (say) 25V? AI: Olin's transistor ...
H: Can a lead-acid battery charger be used for "Gel" type? I have a PB-600-24 lead acid battery charger. Can I use it for the battery type that has an image as below? 4 of the batteries are in series. AI: Yes a gel battery is just another name for sealed lead acid battery or SLA and your charger clearly states that i...
H: Formula calculation and printing negative value. I am successfully reading external ADC value using ATmega32-A. Unsigned int adc; adc = AD7798_16(0x58, 0xFFFF); // read register printf("ADC value is %d\r\n", adc); I am getting ADC value as decimal number range between "0 to ...
H: Multiplex dip switch input to microcontroller I have 3 DIP switch packages with 8 switches each, and not enough inputs on my microcontroller. This article (you have to download the pdf to see the schematic) gives an example of what I want to do. In the comments section, many people say the circuit won't work. I dis...
H: What's the use of the bypass capacitor on the LM380 amplifier? I've read the LM380 amplifier data sheet and application notes, and they show a power supply ripple rejection number that's based on the size of the bypass capacitor. There are also a few designs that use trimmer potentiometers into the bypass pin. Othe...
H: What does it mean for amplifiers to be stable only down to N gain, where N > unity? This is related to What's special about "unity-gain stable"? which is about unity gain stability. But what exactly does it mean if some op-amp is said to be only stable to, say, gain 3 rather than all the way down to unity gain? Gue...
H: Problem with MPLAB's toolsuite I'm taking a module at University that involves MPLab. I'm trying to get it setup at home and so far its been a little tricky. I've got my files from University which I've attached below - if there any help in regards to finding out what language toolsuite I need to use, then that wou...
H: High-pitched noise from boost converter. Need your help I'm experiencing some high-pitched squealing noise from my boost converter, I'm getting some resonating frequency when I start increasing the load current.The inductor is a 47uH inductor. The part number for the diode is MBRD640CTT4G. This is my schematic: [...
H: MOSFET Over Heating. So hot it's melting the solder Alright, continuing with the debugging of my new board tonight I found another issue worse than the one before: My switching MOSFET is getting so hot that I'm getting molten solder. I replaced the MOSFET with a short circuit just to see if the components soroundi...
H: Unexpected pulses in the output signal from IR Detector I have a Sharp GP1UX311QS IR detector connected to a msp430 launchpad. I wrote a small bit of code to read the output signal from the detector and print the on/off times. However, without emitting any IR light (from a remote) a small pulse appears on the outpu...
H: Logic Analyzer Basics I am buying a second hand logic analyzer (Agilent 1661A) and I see the terminology such as the following: 100MHz State Speed Maximum Conventional Timing Rate: 250 MHz full channel, 500 MHz half channel Maximum Timing with Glitch Rate: 125 MHz half channel And there are many more. I expect ...
H: Connecting a 12.5VDC switch output to a GlobalStar SmartOne GPS unit I have a device (hermetically sealed onboard computer on a diesel generator) with a power switch that is connected directly to a lead acid battery (~12.5VDC). I would like to trigger a gps device when the on switch is closed. Although I cannot fin...
H: Can FPGAs dynamically modify their logic? It would be theoretically possible for an FPGA to write a configuration image to an external memory, and load the configuration image from the memory to reconfigure itself. This would be "non-dynamic" reconfiguration. Do FPGAs have the ability to rewire their logic fabric d...
H: Why is the Triode operating region of a MOSFET named such? If triodes were used for amplifiers, why is the triode region generally used for digital and the saturation region generally used for analog? Am I missing a fundamental understanding of the MOSFET's characteristics? AI: Why is the Triode operating region of...
H: What kind of diode to use with ADC inputs I am looking for diodes to protect my ADC from over voltage conditions. From what I have researched so far, I know that I need schottky diodes hooked up from the input to the ground and the input to the VCC line, but I am confused of what properties of the diodes that I nee...
H: Exam question: measure amplifier \$h_{oe}\$ using a signal generator and oscilloscope I'm running through some old exam papers at the moment and one of the questions are: The parameter \$h_{oe}\$ is needed to calculate the output impedance of an amplifier. Explain in detail how to measure the parameter \$h_{oe}\$...
H: Integrating Signals Yes that simple, Can someone explain what the main purpose is behind integrating an incoming signal? What advantages does this offer over lets say reading the voltage directly with an A/D? How does this function as a low-pass filter? Ive seen the schematics and understand how they work, just try...
H: Can I add buttons to the Arduino ide that automates selection of serial port, board then compiles and uploads I am developing four different Arduino projects. I want to have a button on the tool bar for each project that automatically compiles uploads using a fixed board and port. AI: The only way to do that with t...
H: 1S Lipo Powered BLDC Motor Control? I have a 1S Lipo battery, and would like to drive a micro brushless motor at upwards of 6 Amps. I'm trying to design the h-bridges using 2 N channel mosfets each, but ran into the issue of finding a high-side/low-side driver that will drive mosfets at low voltages. Am I just comp...
H: Critique my Soft-start circuit I've been working on a soft-start circuit to solve an inrush current problem that is causing some sparking when I hotplug my power supply into my board. I played around with different solutions and this is the one I like the best so far. It adds a delay of 250ms between Vin and Vout o...
H: How do I dead bug solder this SOT-23 to my PCB? I swapped the base and emitter of my NPN transistor land pattern. If I flip over the part, the pins are in the correct orientation, although there is a 1mm between the pins and the pads. When I tried to solder one I just made a mess. I soldered wire wrap wire in the v...
H: Designing a simple ALU I need to design an ALU with two 8-bit inputs A and B and control inputs x, y, and z that supports the following operations: x y z | operation 0 0 0 | S = A-B 0 0 1 | S = A+B 0 1 0 | S = A*8 0 1 1 | S = A/8 1 0 0 | S = A NAND B (bitwise) 1 0 1 | S = A XOR B (bitwise...
H: Arduino serial via python not working I have a arduino running with bitlash running on it connected to a shiftbrite. I can use a terminal program to send it commands such as rgb(1023,0,1023) and it will work but when I do it with python it doesn't. Here is my python code. I don't know why it doesn't work. I can eve...
H: Would replacing a resistor by another one of identical value but higher power rating affect the working of a circuit? The schematic recommends using 20 Ω 1W as collector resistance. What I have at hand are two 10 Ω rated for 10W. I'm guessing the change should be acceptable ... What difference would it make if i we...
H: AC analysis from a DC fresh grad/point of view So i was finished taking DC circuits and im adept at basic laws like KCL, KVL and Ohms. But today im taking AC circuits and i wondered why things dont work well as before. Lets take this example A series RL circuit is connected to a 110-V ac source. If the voltage acr...
H: Latching power switch question I have the following circuit (source: EDN): I understand the basic working principle of the circuit and it works fine when it is powered from a 1.5V source. But when I power the circuit from a 9V source, by default it get's turned on instead of turning on only when the S1 switch is pu...
H: Does there exist an IC that allows on-the-fly routing of signals? Do there exist ICs with N input pins and N output pins which, either via EEPROM setting or via on-the-fly control by a microcontroller, allow one to route each of the N inputs to ANY of the N outputs? In other words, for example, one might use it to ...
H: Prototyping with a very small surface mount connector/socket I've got a Satellite modem with a connector that mates with a tiny 10pin by 10pin Samtec SS4 series surface mount connector. The question is, how would I prototype with this component? I am thinking I will need to get a custom breakout board created and s...
H: Using impulse response to control the system This post by Olin Lathrop is rather inspiring. The system response is the convolution of the control input with this impulse response, computed every control sample, which is every 500 ms in this example. To make control system out of this you work it backwards t...
H: Hardware Defined Byte I would like to make a PCB that sends a specific byte of information through a usb connection. I need the PCB to be as small and simple as possible to fit into a nice thin housing. Simply put there would be a push button that would send a byte of information identifying it had been pushed, wit...
H: Logic needed to read and store values I am new to programming. I have one input signal from waveform generator. I am giving this signal to one sensor and as well as channel 1 of multiplexer. The sensor output is giving to channel 2 of multiplexer. If sensor output is low then I am using some amplification, the sign...
H: Circuit short circuit capacitor question confusion I am really unsure about how to go about this question and which circuits to consider. Here's the question: Determine the value of the current labeled \$i\$ and the voltage labeled \$v\$ at \$t=0+\$, \$t=1.5ms\$, and \$t = 3.0ms\$. The circuit is as follows: si...
H: Understanding electrical consumption I have problems understanding the difference between electrical power and consumption. Can you help me understand what electrical energy consumption is? Let's say that I have a bulb, on which is written 100 W. How much does this bulb consume in 1 hour? Can it have a power lower ...
H: Input impedance of a GenRad 2512 Spectrum Analyzer Does anyone know the input impedance on the General Radio Model 2512 Spectrum Analyzer? AI: Well according to this document on page 351 it's 1Meg Ohm with a shunted 115pF cap. http://www.scribd.com/doc/66163879/General-Radio-Handbook-of-Noise-Measurement-by-Arno...
H: How do I solder headers so that they always stand straight up? When soldering headers, usually single and double pins, I flip the board over so the pin rests on the surface and then solder them. They never come out straight. It would be great if someone has figured out how to do this correctly? AI: Solder ONE PIN. ...
H: Resistor value labeling, what does the second number refer to? Possible Duplicate: µ in the Middle of a Capacitor Rating What does 3V3 or 1V8 mean I have been looking over some schematics for an industrial Laser. Some resistors which have low values, say 100 Ohms, are labelled 100R. Makes sense. Same goes for 10...
H: LF398 Sample and Hold Circuit I'm having a problem designing a circuit to interface an LF398. On it's data sheet it says that it needs +5 and -5 volts, but I only have +5. My questions are: Can I put V+ on 5V and V- on ground and still have a viable circuit and how would this constrain my input values? Is there a...
H: How to start implementing your own computer? The question As a first step I need to select a circuit board, CPU & RAM/ROM chips and I/O connectors. How do I select a board that can interconnect all these components? Perhaps you could give examples of a full configuration (board and chip models). What type of board ...
H: BBQ iginter power surge I am building a home beer brewing rig that has several electrically actuated components controlled by an Arduino. The typical scheme is Arduino -> Shift Register -> Relay -> Component. One of the components is an electrical BBQ igniter. The problem is that when I turn it on, the shift regist...
H: What is the polarity of a car cigarette lighter adapter? There is a center pin, and two outside tabs. Which are positive and negative? AI: Every car that I have seen had center-positive cigarette lighter 'sockets'. All (as far as I know) modern cars use negative ground systems, so the outer negative 'body' is ve...
H: 9v AC 2000mA power adaptor for a 9v AC 1000mA device Possible Duplicate: Choosing power supply, how to get the voltage and current ratings? I need to replace a 9v AC 1000mA adapter for a 9v AC 1000mA device but all I've been able to find is a 9v AC 2000mA adapter. Will this work or will it fry my device? AI: Yes...
H: 110V AC/ 9V AC power adapter (America) Vs. 220V AC/ 9V AC power adapter (Europe) Possible Duplicate: Choosing power supply, how to get the voltage and current ratings? I have a device that I brought to Europe from America. It has a 110V AC/ 9V AC power adapter that stopped working. Over here I found a 220V AC/ 9...
H: Explanation for Differing Stator Winding Orientations As a layperson, I'm trying to understand the basic configuration for an induction motor or generator. I've looked at many diagrams and photos/cutaways of stator wiring and I've noticed two different orientations for the windings: All the diagrams/photos I've see...
H: Potential difference across one resistor with and without a known current? Okay imagine you have a voltage supply of 10V and one Resistor of 5 Ohms. Now find the current : I=5/10 = 0.5A So potential difference across that resistor : V=IR=10V .. which proves this statement I found in my lecture note : If no intern...
H: tablet as a keyboard (bluetooth / USB) what would it take to get a tablet to communicate with a desktop via bluetooth (or USB)? There are some programs such as remotemouse which do this through WLAN. AI: Get an android tablet, root it, and run blueputdroid. This is not related to electrical engineering.
H: grounding connection? What's the easiest way to connect a ring terminal to the ground terminal of an AC outlet? Are there plugs you can buy that make this easy? I don't need (or want) the line and neutral wires accessible, just the ground terminal, for safety reasons. AI: Another option is to get a replacement plug...
H: Why do I get gibrish output to the serial monitor of my arduino mega 2560? All - Why does my Arduino 2560 report text that looks like this: I©ä I©ä !11<]=I1)!11<]=I1)!11<]=I1!11<]=I1)!11<]=I1©ä é ©ä I©ä I©ä I©ä I© Every time I execute "spi_dev_test" from my raspberry pi? I have been trying to follow the instructio...
H: after programming PIC, can no longer run debug or reprogram OK, I have written a few basic programs in MPLABX C18 for both 18f4550 and 18f46k20. Eventually got them to compile and test/debug correctly and run on the PIC. After I choose, "make and program device" It works but I can no longer run debug or re-progra...
H: Reading a PIC datasheet Reading MCU and component datasheets is a whole new skill to me. I have a wire that I want to monitor as high/low (1/0) voltage, using a PIC10F200. (datasheet) I presume somewhere in the datasheet the min/max voltage an IO pin configured as input guarantees to read 1 or 0 is defined. Can som...
H: Name this electronic connector Pins = 16x2 Space between pins = around 2mm What i really need is the name of a female adaptor to connect to it in order to have cables like this. Thanks! AI: DIL / dual-in-line header. These are available with insulation displacement connectors (IDC) allowing termination to ribbon c...
H: Is it possible to intercept the audio data of voice call in Android? To my konwledge, the (voice call) audio data from micphone will be sent to PCM module for resampling, then to modem for coding before sending to air.I am here for asking in Android is it possible to intercept the audio data from PCM to modem? Beca...
H: 10-bit digital representation with SPDT switches and voltage division I'm completely new to electronics, and have been trying to come up with a way to connect 10 SPDT switches to a single analog pin on my Ardiono Mega 2560 (and off course connected to 5V and Ground). The idea is to enable as many switches on a sing...
H: RS232 concurrent communication I need to interface with a printer equipped with a RS232 port from both my arduino microcontroller and my computer. It means that the printer is connected to the computer through the RS232 port and I would like to connect an arduino card to the same RS232 port in order to send some co...
H: *EP pin connect to Ground I was just wondering what is the function of the *EP pin on most TQFN package chips? It says I should connect EP to ground, what happens if I don't ground it (I forgot)? AI: You talking about the pad on the underside of the part? Most likely that's there to dissipate heat. People like t...
H: Op-amps that get really close to the supply voltage I've heard that I can get an Op-amp that will be able to get it's output to within a few millivolts of the supply voltage. Do these exist? If so then where or how do I find them. If you want specifics, it needs to be able to work at 3.6 volts, have two op-amps and...
H: Multiplex two displays or use a higher pin count uC? I am currently learning to program a NXP LPC1347 for a project which will utilize two SSD1963 controller-based displays. The issue is that the uC only has 51 IO pins whereas the total pins of the display would amount to 26. This leaves too few pins for the periph...
H: What is static/dynamic power? I'm learning about power management in OMAP35x and I came across these terms. I can't seem to find a good explanation anywhere. What do they mean? AI: Static means the power it will always draw no matter what you do, typically this is due to transistor leakage. Dynamic power will vary...
H: Why am I not arriving to non-inverting amplifier equation? I was trying to derive the non-inverting amplifier equation and I ran into some trouble deriving it. By making the voltage between R1 and R2 VRef, I set my equation to Vin - VRef = Vout. Because VRef = Vout(R1/(R1+R2)), this means Vin - Vout(R1/(R1+R2)) = ...
H: Keyboard vs mouse power consumption I have a wireless keyboard (logitech pro 2000) and I have not changed its batteries (2 AA) for about 6 months, not even once! On the other hand, I have a wireless mouse (logitech performance mouse mx) and by golly I have to change its battery (1 AA) every 1-1½ week! One could say...
H: Will my Arduino output pin at 0v handle 25 LEDs cathodes Short question: Is it safe to connect a single Arduino ADK (Mega) output pin at 0v to 25 LEDs, each with an appopriate 100 ohm resistor, and each being powered by a output pin at 5v? i.e. 25 output pins at 5v each connected to an anode of one of 25 LEDs with ...
H: Transistor question and is my circuit safe for Raspberry-Pi? This is my first circuit designed from scratch (that actually does something interesting), so please be patient with the beginner's mistakes (and maybe point them to me). My circuit is the following: What the circuit does is: When switch SW1 is open, th...
H: Wifi device with directional antenna and programmable power I need to set up a cheap device for an experiment that sends Wifi signal in a single direction but also allows me to set the power level on the Wifi signal. I've tried to find a solution and looked at Arduino shields etc. but haven't found anything suitabl...
H: Transfer Function and Bode Plot from Poles and Zeroes I've got the following bode plot from a black box: I've calculated the zero to be 1055 and pole to be 67. Thus I'm using the transfer function \$H(s) = (s-1055)/(s-67)\$ but this gives a clearly wrong bode plot: WolframAlpha calculation I'm guessing my transf...
H: Is the theory of operation behind my FPGA design acceptable? (This question is somewhat related to a previous question of mine.) I'm trying to use an FPGA to drive an LED strip which contains several WS2801 ICs. (WS2801 datasheet) The operating premise of the WS2801 is simple - clock in 24 bits of data (8 bits each...
H: The reading distance limit on passive RFID It appears that nearly all "passive RFID" tag-reader combinations have around a 5-10cm specification for reading distance. But I am interested in approx. 20 cm reading distance. I am assuming one of these is the right approach to follow, but I'm not sure which: Perhaps th...
H: Compare implementing a simple automation design on a MCU vs an FPGA/CPLD I have been working with MCU's since the 90's, and I've recently ventured into the FPGA scene with the Spartan6 series chips from Xilinx. Assuming a simple factory automation design with sensors and motors, and some intelligence to link everyt...
H: Ground copper pour for Crystals and Real time clocks I am laying out a (2-layer) board, with a standard SMD Crystal as well as a Real-time clock placed on the top-side of the board. What are guidelines regarding ground copper pour under the Crystal and under the RTC, for their optimal performance? In other words, s...
H: Speed of electricity (signal propagation?) through copper for communications delay I would like to be be able to calculate the delay for communications data within TCP/IP networking through cat5e networking cable. That is a pretty vague request so I will do my best to clarify (it is very likely I am missing a pi...
H: Can shutting of power bar damage cables or modem? I switch off the power bar which has my modem and computer plugged into it a few times per day. Two days ago, a technician changed the wiring since my Internet completely stopped working for the second time. I am wondering if turning off the power bar is damaging th...
H: Amount of current after DC/DC conversion for PC/104 Let say I have a AC to DC adapter with output 19V 7.9A connected to a 150W DC to DC power supply board (PC/104) with input 14-30V and output 5V. What is amount of current I'll get from the 5V output board? Is it 150W/5V = 30A or 7.9A? Sorry if this is so primitiv...
H: How to calculate phase shift between two sine wavefroms I two sinewave signals with same frequency. I want to measure phase shift between two signals. There will be a small phase difference between two signals. I am using ATmega32-A micro controller and external ADC AD7798 to read the voltage of both signal. I am a...
H: Arduino + Escudo + EL Wire on analog port: need pull-up-down resistor? I am using a pair of El Escudo boards on my arduino. I've stacked them and fed the digital I/O pins to the first one and manually wired the analog pins to the second one. All works fine - sort of. I wanted more than eight wire segments, so I tho...
H: IR-Receiver signal almost constant I have followed the tutorial from Makezine about an Infrared heart-beat sensor, and I have essentially used the same components listed on the video (that is, the same resistors and the same IR Emitter and Detector). So, with a simple source-code just reading the analog output and...
H: V-USB with ATtiny2313 to communicate with Android How would one interface a ATtiny2313 with usb to communicate with a android device? I know it involves using V-USB, but how does the circuitry work? Am I supposed to connect certain pins on the ATtiny2313 to certains parts of a usb head? (How do I connect the ATtiny...