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8 votes
5 answers
1k views

What are some of the more compelling use cases for plug computers? [closed]

Are plug computers useful for anything besides network-attached storage? I know that you can hang a bunch of drives off them, maybe set up your own web server. But those uses have limited ...
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22 votes
11 answers
30k views

Injecting a communication signal over DC power supply lines

I'd like to be able to daisy chain multiple devices using just the power supply wires and then inject a communications signal over the power lines to turn it into a half duplex network. Are there any ...
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  • 1,760
20 votes
4 answers
21k views

How does an audio jack detect when a speaker is plugged in?

Some sound card audio jacks can now inform recent Windows OS's that an audio device is plugged in. Anyone know how it does this? I'm thinking it uses some kind of voltage comparator or resistance ...
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  • 303
3 votes
2 answers
2k views

Inductor for LM2575

Can anyone suggest a 330uH inductor and associated Eagle .lbr for use with an LM2575? I've been looking all day for this! Any suggestions would be appreciated.
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23 votes
10 answers
18k views

Cheap 1MHz oscilloscope

I'm learning electronics (and basic electricity) and I wondered if a 1MHz oscilloscope like the DSO Nano is enough for (very) basic electrical and/or electronic circuits. I'm almost broke and I need a ...
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  • 233
17 votes
2 answers
3k views

How might you use a LiPo battery as backup for mains power loss?

Many people seem to run their projects off the mains (e.g. with a wall wart) or from a battery, but there doesn't seem to be too much discussion about how to run a device off the mains, charging a ...
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  • 1,569
19 votes
6 answers
13k views

Reusing laptop monitors

I have a 17" laptop monitor with a 1920x1200 (WUXGA I beleive it's called? or just UXGA?) resolution which I simply love. Now, assuming the laptop dies before the monitor does, would anyone know if it ...
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  • 293
9 votes
3 answers
653 views

What is a sensible approach to connecting devices to your computer via wireless technology?

I remember with fondness the X-10 days, when you could connect your computer to every wall plate in your house, using power-line carrier to transmit signals to addressable receivers (with varying ...
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6 votes
3 answers
10k views

Is there any way to determine the correct voltage for a stepper motor?

I recently bought a CNC mini-mill at an auction. It is fitted with steppers on the three axis. The X and Y are the same, and the Z is a bit smaller (physically). All the markings were removed from the ...
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  • 1,132
20 votes
8 answers
44k views

How many individual lights can an arduino control

I want to use a regular Arduino board to control LEDs - what is the most lights I can control individually from the board? Is there a tutorial on how to hook it up?
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  • 4,950
6 votes
2 answers
2k views

Can I combine the power supply?

Here's the circuit I'm working on, it's a robotic stringed musical instrument thing, that uses 6 DC motors and an Arduino Duemilanove - The resistors are 0.25w 1KΩ The transistors are TIP122 ...
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  • 3,275
7 votes
3 answers
2k views

Prototyping a part with 2mm spacing on 0.1" matrix board?

I have an Airwave AWM682RX 5.8GHz video received and matching AWM683TX transmitter module. Oddly, one has pins spaced at 0.1", the other at 2mm. So, what's the best way to make a part with 2mm spaced ...
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  • 793
56 votes
5 answers
90k views

Stripboard/veroboard/matrix board design software

I'm prototyping a simple layout for a small project on matrix board, but figured there must be a better way than drawing it all out on paper. Are there any aimed at matrix board? I've found the ...
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  • 793
9 votes
2 answers
527 views

Batteries for 12- to 24-V motors

I have some nice gear motors that run on 12 to 24 volts, and want to use them in a medium-sized mobile robot -- maybe 30 cm * 30 cm for the base. I only expect it to run indoors, or possibly outside ...
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19 votes
6 answers
12k views

Simple Circuit Simulation tutorial

For the last few days I have been trying without any luck to find a good tutorial on simple circuit simulations. I am a relatively new hobbyist and I figure if I use simulations and play around the ...
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  • 3,847
5 votes
3 answers
410 views

How to supply power from vehicle to a low power device?

I am a programmer with only basic understanding of electronics/electricity. I am trying to install this device into my vehicle. The device accepts a wide DC power input (10V to 30V), but has a ...
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  • 193
2 votes
3 answers
828 views

How do I program an AVR Raven with Linux or a Mac?

This tutorial starts with programming the Ravens and Jackdaw with a Windows box. Can I do those initial steps with a Linux or OS X machine instead? If so, how? Is there any risk of bricking the ...
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4 votes
3 answers
15k views

Hooking up an LCD to Arduino Diagram

Has anyone got a really clear diagram of the way to link up a 16x2 LCD screen to an Arduino? Basically I have an LCD for which the back light is coming on, but I am not getting any words appearing on ...
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  • 4,950
2 votes
1 answer
301 views

Cases for Phidgets boards [closed]

Are there cases for Phidgets IO boards such as the 1019 ?
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  • 545
4 votes
4 answers
838 views

1.25-28V var. power supply mod

I have a 1.25 to 28 V variable power supply I'm working on. here's the schematic (from here): What I'd like to do is put in a fan (12v 0.16A) so it runs when i turn it on, however i don't know where ...
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  • 291
2 votes
1 answer
264 views

Develop Snap-On Board For Easy Connections - Rabbit SBC

At my Company, we are using the BL2600 (Seen here) to create a new automation controller to replace our older controller. Rather than have electricians have to terminate wires into a Molex connector ...
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4 votes
3 answers
3k views

Using Arduino to program Amtel AVRs via ICSP header

I have an Arduino (NG) board with an ATMEGA168 AVR micro. The board has a 6 pin ICSP header. Here is what I propose to do, please tell me if it is possible: Remove current ATMEGA168 IC Replace with a ...
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  • 285
28 votes
6 answers
18k views

How do I physically work with a hobby motor?

How do I incorporate a hobby-style motor into a project, physically. How do I mount it and connect a wheel to it? (Assume that I have a working H-bridge or even switches, and am not concerned about ...
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4 votes
5 answers
2k views

MSP430 programmer

I was hoping you would share with me info on making my own board for programming. I recently came into a handful of MSP430F20xx that I'd like to play around with, but my student budget isn't offering ...
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4 votes
1 answer
1k views

Arduino Speed Controllers for RC Cars

This may be a lame question but, Speed controllers on big RC cars can they be controlled from Arduino? If yes, do they have a standart? do I control them using PWM values? What should i look for if I ...
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4 votes
1 answer
129 views

Specs on Siliconix SSTC34-T1

I have been gifted about 2/3 of a reel (2000-ish) of these SOT-23 parts but I cannot locate any data for them. Can anyone point me in the right direction. Through the various datasheet sites I have ...
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  • 131
2 votes
4 answers
169 views

Dealing with excess heat

As a sort of weird side project, I'd like to make an oven timer that has selectable food stuffs and associated timing information. Now while this device would be simple to make I would like to stick ...
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  • 4,977
3 votes
4 answers
2k views

newbie code query => Arduino & DS18B20

been using picaxe for a few years but now playign with arduino and trying to learn how it all works. I have a couple of arduinos talking via the HOPERF library successfully and now want to send some ...
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4 votes
2 answers
1k views

AVR Stick Data Logger Usage

Has anyone used this data logger (or similar) with v-usb to collect data? http://www.sparkfun.com/commerce/product_info.php?products_id=9147 If so, what is the maximum times per second voltage data ...
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7 votes
1 answer
850 views

Help with connector part numbers

I need a really small 2-pin connector, a cable connector on one side, and a surface-mount jack on the other. These two items at AllElectronics are pretty close: Small Battery Connector, 2mm spacing ...
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  • 4,606
21 votes
9 answers
5k views

Sizing SMD components for Hobbyist Kits

More components are only available in SMD packages. For hobbyist assembly the options are to buy breakout boards or solder SMD. Since components are usually packaged in a couple of SMD package ...
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  • 11.5k
5 votes
2 answers
1k views

Arduino Tweeting Weather Station [closed]

I want to create an Arduino Weather Station with Temperature Rain Gauge Wind Speed Wind Direction Humidity What peripherals should I be looking at getting? Ideally I want this project to tweet the ...
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  • 361
2 votes
2 answers
5k views

Programming a PICAXE with an Arduino

Can you program a PICAXE microcontroller with an Arduino Duemilanove Maybe with the ICSP (6 pin) header?
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  • 4,950
5 votes
5 answers
4k views

How to deal with a DC adapter with irregular voltage output?

Background information: I tried hard to get a Schmitt-trigger working, but it kept failing. By accident I figured out, that my AC-to-DC adapter produces a very irregular voltage output (I could hear ...
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6 votes
2 answers
11k views

Arduino Vin Pin

This maybe a very stupid question but, how much power is available via Vin pin? I am assuming it is 5 volts, but how much amps are provided? EDIT: I am trying to run a dc motor using ardumoto shield,...
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7 votes
3 answers
983 views

Simple (?) pressure activated sound

I'm thinking about putting together something simple for my young son's soccer team. I'd like to build a simple circuit that could be placed on/underneath the laces of their shoes and plays a sound ...
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  • 73
1 vote
2 answers
1k views

Arduino Ardumoto

I am using Arduino and Ardumoto dc motor controller to drive a DC motor. I am kind of at lost because i have gone through 10 different motors. They either don't work( not enough power ) or not ...
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9 votes
1 answer
4k views

Easily controlled color LCD for hobby projects?

I'm looking for some not too expensive, easy to control color graphics LCD I can use for various hobby projects, along with an AVR microcontroller or maybe an ARM in the future. The cheaper the better,...
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  • 6,782
3 votes
2 answers
3k views

AVRISP MKII does not appear in AVRStudio 4 (latest build 4.18 SP1)

I have a AVRISP MKII that I wish to program avr chips with through avrstudio 4 with. However on the "select platform" the only think that resembles MKII is JTAGICE MKII which is not what I have? Am ...
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  • 547
6 votes
2 answers
3k views

What MCU, need hi res ADCs?

I'm trying to find a powerful MCU that has multiple analogue to digital converters. I want around a 14 bit resolution to do some serious audio sampling. Any suggestions or comments would be great, ...
7 votes
2 answers
2k views

What is the reasoning for the arithmetic functions on the 74181?

I don't understand why the 74181 operates the way it does. It does provide the full set of logic functionality (AND, NAND, OR, NOR, XOR, shift),but its arithmetic functionalities are not so clear. For ...
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  • 271
8 votes
2 answers
10k views

How to build disco lights?

When I was a teen, I joined an electronics club and built a disco board. I had 5 light bulbs, I painted them different colors. Then I built a board which was connected to these light bulbs. I'd ...
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7 votes
4 answers
390 views

sensing light and outputing voltage suitable for audio

I have an idea for a project where I use a pc fan to make an oscillator. The oscillation is created by the cycle of light/dark falling on a light sensor as the blades of the fan rotate. My initial ...
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  • 285
11 votes
6 answers
13k views

DIY USB Mass Storage Tutorial

I was just wondering if there was a tutorial anywhere on how to make your own USB Flash Drive and I don't mean take apart a USB and put the guts into something else, I mean put together the flash ...
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  • 263
34 votes
2 answers
13k views

How to calculate battery life

How do I calculate how long a battery operated product will run? Here's what I've got: 2 AA, 1.5V, 2700mAH batteries Voltage Regulator with a Iq of 25 uA Voltage Regulator Eff = 80% Active Current = ...
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  • 3,212
5 votes
2 answers
1k views

How to test if it is a non-multiplexed (static) LCD?

I got some static LCD's from an old cheap clock, calculator and the like and now I would like to use them for displaying simple things like temperature. They are connected with those pink with grey ...
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  • 339
3 votes
6 answers
10k views

Calculate G's of an Accelerometer

Pat asks: Accelerometer Breakout Board - ADXL193 +/-250g could you tell me if this is correct. Looking at the data sheet the mid sensitivity is about 8mv/G @ 5volts. If I use a 10bit adc @ 5volts ...
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  • 4,950
1 vote
2 answers
2k views

power supply unit for Arduino/solenoid project

I'm trying to find an off the shelf plug in ac/dc power supply unit to work with my project. I want to power an Arduino Duemilanove and six 12v 1A solenoids. Here's the solenoids -> http://www....
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  • 3,275
8 votes
2 answers
3k views

Good analog design learning project

My college undergraduate electronics classes covered some analog design, and I'd like to further my knowledge and experience. What would be a good project that would require significant effort as far ...
32 votes
12 answers
33k views

Opinions on an oscilloscope suitable for hobby electronics on a budget

I'm thinking about getting an oscilloscope as my next tool purchase but I don't really know what I should be looking for or what the options are. Ideally I'd prefer something that was stand alone, but ...
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  • 1,070

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