# All Questions

119,321 questions
965 views

### Detecting which pins are inputs or outputs

I have an idea to make a device with a generic ZIF socket which can be used to identify any chip you place into it and once identified run a suite of tests to verify that the chip is functional. I ...
2k views

### Which standard dictates how reference designations should be formed in the EU?

I'm studying electronics in college (I live in Europe), and they are teaching us we should form our reference designations of elements when designing a circuit as according to EN 81346. This seems ...
836 views

### Communication between AVR and CORUS PTZ device

12 NULL bytes are being sent to CORUS device (to power on it) with this codevision code like putchar('\0'); Sending is ok , but regarding to page 9 of the ...
2k views

### Powering 1.8v GPS with Arduino

I want to purchase this new GPS on sparkfun, but I have no idea how to get the correct supply voltage (1.8vdc) for it from the Arduino. 48 Channel GP-2106 SiRF IV GPS Receiver Datasheet
1k views

### Can a 110v spa pump curcuit control a 220v spa heater that is on it's own 220v circuit?

I have a 110v spa pump that is itself controlled (on/off) by an air switch. I want to install a spa heater that is 220v, but when I purchased the heater I didn't realize that the heater should only ...
769 views

### Dual voltage LED circuit

I am designing a board that will eventually be connected to a front panel with LEDs. In the meantime, I have a set of LEDs mounted on the board itself for debugging and whatnot. To debug this board I ...
3k views

### The 'gap' between understanding of transistors and their application in real circuits

How do they even work? I'm in senior high school year and have electronics as a subject. I'm really interested in getting to understand this and take up electronics in college too. But now this seems ...
350 views

### What is the difference between Micro-controller and Micro-Processor? [duplicate]

Possible Duplicate: What's the difference between a microcontroller and a microprocessor? I am new to the micro-controllers and yet I don’t know much about that. While reading a book about ...
760 views

### how to design an inductor in Tanner L-edit and extract the designed layout in L-edit to S-edit?

hello i am trying to design an inductor in L-edit. i thought to use metal1 layer and make a squares in it for example 5 squares while there is a free hole in the center of them. actually i don't ...
527 views

### What is failure analysis of PBCA?

I do not know whether this is the appropriate place to post this question but i guess its related to electronics. Basically i'm doing some research on what is the term for "PBCA" in failure analysis? ...
5k views

### Building a RFID-Zapper from the scratch

I would like to build an RFID-Zapper from the scratch (not based on a camera flash). Since it is working with a high voltage, I prefer to ask first. Does this look OK to you? The capacitor is 330µF,...
620 views

### Voltage dividers and resistors

I just encountered the voltage divider a few days back. It was working, yes. But i'm confused that in my circuit, I needed to output 1/2 voltage so I used equal values for the two resistors. And from ...
376 views

### Microcontroler with external bus

I am looking for some microcontroler with external bus for program memory, and witch is supported by GCC. I read this Atmel ATSam3U datasheet (I have no experience with this familly, yet) and there ...
714 views

### Circuit to exaggerate differences in current

Basically what I am after is some sort of a circuit which will amplify higher voltage signals, but possibly dampen lower voltage signals, in order to make a wider separation between high and low ...
12k views

### Composite/RGB Video from simple hardware

I'm designing a 68000-based VGM player, and I'd like it to output some sort of 'visualization' of the currently playing song to a TV through either RGB or Composite (video encoder probably for that.) ...
6k views

### Op Amp based Hartley oscillator

I would like to build an oscillator that will satisfy a few requirements. The main requirement is to have exactly one capacitor. Another one is to have high Q and sine wave output. I am considering ...
2k views

### Can I use a voltage divider and/or voltage follower to produce 1V from 9V for an op-amp oscillator?

For a circuit I'm building, I'm using an op-amp oscillator to generate a sine wave. The sine wave will have a maximum voltage of 1V and a minimum voltage of -1V. The circuit will be powered by a 9V ...
23k views

### What is causing large oscillations in my DC/DC boost converter? Is this ground bounce or some other effect?

I designed my first PCB for a DC-DC boost converter only to find that it produced very noisy output. The design is based around the MIC2253. Here's a schematic: Although my circuit allows for ...
277 views

### Reading a simple diagram, how to practically implement this on a breadboard

So yes, I'm brand new to circuitry, and I'm looking to implement a very simple diagram in order to boost a 3.3v output to 12v output. I've picked up a lm317T from the local electronics shop and I'm ...
321 views

### Cross-CPU Communications

So - I have a little situation. I have a MC68000 as my system's main CPU, and a 68008 as my sound CPU to interface with a YM2612 and my RGB video generator. Right now, I'm just going to stop the sub ...
2k views

### When looking for resistors, what is the W for?

I'm looking for a variety of resistors for my project. Since I'm so new to this, I don't have the slightest idea what I'm looking at. Essentially, as I research ideas, I get recommendations that ...
1k views

### Alternatives to multisim

Could someone tell me alternatives to multisim for simulating pic microcontrollers. Free alternatives , not just the free demo version of Proteus. Thanks
1k views

### Assembly Packed Bcd

I was trying to make a subroutine called count that will count the number of occurences of the string ‘hello’ in the 64 KB external memory with 8051 microprocessor. What i wanted to make is that ...
408 views

### How to communicate with parallel eeprom with pic18f?

How to read eeprom M27C64A with pic18f4520, should i enable and disable the chip enable as well as output enable inside the loop while increasing the address? Can someone suggest me some code or ...
19k views

### Creating a new power source for light-string ornaments

I have a couple Hallmark Star Trek ornaments that plug into Christmas light strings. I'd like to convert the power supply to them from the light string plugged in the wall to a battery pack so I'm ...
2k views

### Where might I find a prefabricated enclosure for a PCB?

I'm working on a small electronics project that includes a micro-controller and a few extra items soldered down to a PCB. This project will need to be contained in a nice chassis/enclosure that can be ...
2k views

### Matching load capacitors to crystal

Edit: Sorry, had messed up the capacitor values as I didn't take into account the values halve per leg. This should be fixed now... I'm needing to attach a crystal to a microcontroller (a PIC16F84A), ...
7k views

### Can I include heatsink copper in a Kicad footprint?

I have some SMD parts that have a recommended copper pattern for heat spreading. Can I include this in a Kicad module? I don't see a convenient way to draw filled copper polygons that aren't pads. I'm ...
4k views

### How fast can a Li-Ion battery be charged?

So far I've seen many Li-Ion battery chargers that do the full charge in about 1,5 hours or more. There're also NiMH battery chargers that claim they charge a NiMH battery in 15 minutes and then the ...
4k views

### Low loss current sink

I'm working on a battery powered device that has 4 individual LED drivers. The output from the LEDs are controlled with separate PWM signals from a small MCU. This has to be low cost, and a low cost ...
598 views

### Circuit diagram and components for Comfortron controller (Chevy, Oldsmobile, …)

I am trying to help repair a Comfortron heating and cooling controller for a late 1960's Chevrolet Impala. The Comfortron is an early climate control system that uses a combined vacuum and electrical ...
2k views

### 3.7V Rechargable battery as arduino power supply

I have an arduino and a telit GM862 module which requires 3.4V-4.2V power supply. So far I have constructed a 12V limiter to plug it into a car power supply and a step-down converter which converts ...
1k views

### charging a lead acid battery

(n00b question) I have a small (6 cell regular bike) leadacid battery and want to charge it via solar sheet of 15V - 0.3A. the voltage solar sheet changes and in cloudy day goes below 10V. does the ...
12k views

### Principal of Analog to digital converter(ADC) and Digital to analog converter(DAC)

Analog to digital converter is one that converts analog output form sensors to digital one what are basic principal of Analog to digital converter(ADC) and the opposite of one that takes digital input ...
580 views

### about Synplify VHDL (code imported from Xilinx ISE)

Good day, Need some help. Start to work with Synopsys Synplify. Import my Xilinx ISE project (fully work). Try to run and receive - "No matching overload for to_integer" for this line ...
1k views

### Circuit to shut off power after a short time of turning on

I've got a 3V button battery driving an led and a trembler switch functioning now. However, the sensitivity of the switch is giving me trouble because I need it to remain open when at rest in a ...
470 views

### CCD for bar-code scanning

I am carrying out some research on CCDs for a h/w design project that I have coming up that would include a 2D bar-code scanner module. I know that there are ready made modules available and thus ...
1k views

### Bidirectional Shift Register

I am designing a project that has around 50 or so outputs and around 20 or so inputs. I have designed a chainable breakout board for a standard '595 shift register for the outputs, and was planning on ...
11k views

### How can send bytes for arduino?

I have developed an app client that sends a string/comand by socket for another pc app server and the app server sends a string for the arduino over the serial port. The problem is: how can I send ...
471 views

### Why can't I send data from a PC to an Arduino?

I developed an app which sends data to an Arduino by serial port, but I can’t t understand how to receive the data in the Arduino. I send a string by serial port to the Arduino and the Arduino ...
4k views

### Arduino interrupts for button input

I have 6 buttons on my printed board, and I'd like to use interrupts on them all, but they don't correspond to the interrupts listed on the specs. Is it true that you cannot choose arbitrary pins to ...
1k views

### RF decode logic (not Manchester encoded) - Arduino

Continuing from my previous post, I am trying to decode the encoded RF data directly on Arduino. I've adopted the "sampling" approach, as against the "interrupt" based approach, reason being I believe ...
61k views

### Creepage distance for PCBs handling line voltage AC?

What is the required creepage (e.g. trace-to-trace) distance for PCBs handling 240VAC rms? What about 120VAC? This is for UL and CE certification. The standards for PCB Creepage (e.g. the distance ...
3k views

### How can I determine the specifications of this LED (photo included)?

This LED (and 8 others like it) form the lighting component of a ceiling fan assembly. Unfortunately, they put out a very dim and cold light, and I'm interested in replacing them, but I figure I need ...
4k views

### When measuring AC via an ADC, is it bad to have common ground?

I've got a circuit that looks like this: circuit http://img.skitch.com/20111127-m6jqyx9b15brese4rkipayyib6.png My input is low voltage AC at low current and I want to measure this with an ADC at 3....
453 views

### How much negative voltage is too much for a µC?

I've been attempting to measure some stuff and trying to be careful about what I feed into my microcontrollers. I've had difficulty figuring out how to keep things within perfect limits, though. For ...
2k views

### Any idea where this surge came from?

I'm playing around with some CTs for measuring appliances. I got two of these SCT-013-030 units and hooked them up to a breadboard with a 5V supply using this circuit I found on the internet: I'm ...
35k views

### How to program STM32 Development Board

I'm a total beginner with programming ARM microcontrollers, but I do have experience with AVR and PIC microcontrollers. A few days back I have purchased a STM32F103VET6 development board from eBay. I'...