64pixels Are Enough

March 21, 2009 by Eliot 7 Comments

64pixel

[Alex] put together this lovely minimal LED project. The square pixel matrix is soldered directly to the microcontroller in the same style as EMSL’s Micro-Readerboard. During the prototyping phase he used resistors to limit the current from the programming board. The final product doesn’t use resistors and manages the current draw by only turning on a single pixel line at a time. The illustrated assembly guide is very thorough and should help your create an equally compact device. Check out a video of it in motion below.

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Smart Card Emulator

March 3, 2009 by Eliot 48 Comments

Here’s a quick prototype from [Travis Goodspeed]. It’s a smart card built around an MSP430 microcontroller. We’ve used the MSP430 in the past because of its low power demands. He says this business card currently supports 1.8V to 3.3V, but a future design will have 5V as well. Technologies like Java Card exist for running applets on smart cards, but a familiar microcontroller like the MSP430 could certainly make development much faster. Knowing [Travis], there’s a reader somewhere about to go through some serious fuzzing.

AVR Mega8 RSS Reader

February 26, 2009 by Caleb Kraft 16 Comments

[Barney_1] built this sereial RSS reader. He’s using the Dragon Rider 500 development board, which is a kit that has expansions available including the LCD, serial interface, and power supply. You don’t need the kit though, you could just build your own with similar specs. He has written a program in python to scrape RSS feeds and send them to the LCD. He’s got some specific workarounds for the Dragon Rider board if you do have one. You can download the firmware and source code on his site. You can see a video of it after the break.

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PropIRC: Propeller Based IRC Client

February 25, 2009 by Caleb Kraft 18 Comments

propeller

Many people don’t want to miss anything in their IRC room, so they “idle” or just leave the client open to capture all the conversations. It can be annoying to have it going in the background on your computer though. To remedy this, [Harrison] built a simple computer from a propeller microcontroller that’s only purpose is to connect to IRC servers. It can take a regular PS2 keyboard and works with a standard monitor at 1024×768. It’s compact size and low power requirements make it quite a useful tool to have around if you are always on IRC. you can download the source code and schematics on the site.

[Thanks Scott]

How-to: Digital Picture Frame, 100% DIY

January 8, 2009 by Ian 50 Comments

frontii

There are a ton of digital picture frame tutorials out there. Most are old laptops with crafty case reconfigurations that fit a photo frame profile.

We set out to build a 100% DIY, scratch-built digital picture frame. Our frame has a 12bit color LCD, gigabytes of storage on common, FAT-formatted microSD cards, and you can build it at home. We’ve got the details below.

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WAP Controlled Home Automation

December 22, 2008 by Eliot 8 Comments

homeauto

[Josh] sent in a home automation project he did a little while ago. It has a total of eight switched outlets. The main focus of the project was WAP access for remote control from any cellphone. The control box is based on a design by [Ashley Roll] for controlling eight servos using a PIC microcontroller. A listener app written in Java monitors the control web page and sends signals to the board via serial port. He used opto-isolated 240V solid state relays for each of the outlets. All the pieces are available on the site and he might even do a custom control board design if there is enough interest.

Working With Relays

December 5, 2008 by Eliot 24 Comments

relay

SparkFun’s latest tutorial shows you how to work with relays. A relay is an electrically operated switch. In this case, they’re using it to switch a 120V AC outlet. The article carries the standard warnings about how not to kill yourself with AC (plus some non sequitor linking throughout). As an extra precaution, they chose a GFI outlet. You probably know how a relay works, but it’s worth seeing how they implemented it. They use a transistor to prevent overloading the microcontroller’s GPIO pin. The control pin is pulled to ground to keep the relay off. A diode is placed across the relay coil to manage the power flow when it discharges. An indicator LED is included to show when the relay closes. This is a great foundation for an automation project, or maybe you just want to terrorize your cat.