Cellular Automata And LED Matrix Fun

October 28, 2008 by Caleb Kraft 7 Comments

Blinkomat, an LED matrix, turned out quite well. 240 LEDs controlled by an Atmega 16 is what we call a decent bookshelf decoration. The dimensions of 12×20 were chosen due to the fact that the microcontroller has 32 I/O lines. The LEDs are switched on and off using multiplexing. The brightness, controlled by pulse width modulation can be varied by 16 levels. The overall effect is quite smooth an fun to look at. He has programmed it to do other things than just cellular automata. Our personal favorite is a simple sine wave. Watch it after the break.

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LED Life And Charlieplexing

October 24, 2008 by Eliot 8 Comments

Yesterday, we featured [Andrew]’s orientation aware camera. We want to highlight another one of his projects: LED Life. It’s a 6×5 LED matrix playing Conway’s Game of Life. He used the low power MSP430 like our e-paper clock. The best part of the writeup is his explanation of how Charlieplexing works. Microcontroller GPIO pins generally have three possible states: output high, output low, and input. This combined with the directional nature LEDs and some creative wiring means you can run a large matrix of individually addressable LEDs with just a few IO pins. Instead of just flipping the IO pins on and off you change their assigned state. Have a look at [Andrew]’s site for some great illustrations of how the system works. A video of his LED Life board is embedded below. Continue reading “LED Life And Charlieplexing” →

Uv Oven From An IKEA Cabinet

October 23, 2008 by Caleb Kraft 7 Comments

This may not be an amazingly complicated project, but it is a very elegant and fairly cheap way of building a UV oven for exposing PCBs. [aris] started with an IKEA FIRA cabinet. He basically left the framework as an empty shell and made a make shift top hinged door to enclose it. Mounted in the top is an array of 35 UV LEDs powered by an HP printer transformer. He did not have a timer circuit, instead he just watched the clock and unplugged it at the right time. You can see from his pictures that his results were quite good.

If you don’t want that piece of furniture taking up room, and don’t mind using a little more elbow grease, you could follow our directions on how to make your own single sided PCB. If money isn’t an issue either, you can always just get your PCBs laser etched.

Rovio Teardown

October 20, 2008 by Caleb Kraft 5 Comments

[Del] sent us what might be the first in an expected plethora of hacks on the Wowee Rovio. He was annoyed by the poor lighting for Rovio’s camera so he cracked it open and started hacking. He found there was just enough space for a couple LEDs in the head. The most difficult part of this was apparently running the wires for power into the main body of the rovio. He said it took him around 30 minutes just to snake the wires through the neck. The final result is best seen in the comparison pictures of rovio looking at Wall-E.

Jar Of Fireflies

October 18, 2008 by Eliot 14 Comments

[Randomskk] has been attempting to make electronic fireflies for quite some time and finally settled on a design he liked. His jar of fireflies uses an ATtiny13 to control a set of 12 matrixed LEDs. The green SMD LEDs are each soldered to a pair of thin wires that hang down into the jar. The software picks an LED at random to flash and then flashes it 1-3 times. The random seed is incremented each time the jar is turned on, so you’ll get 255 different patterns. The power is just a standard coin cell. The project is fairly simple electrically, but the LED soldering could prove difficult. It was inspired by this firefly jar project. Check out [Alex]’s synchronizing fireflies too. A video of the jar is available below. Continue reading “Jar Of Fireflies” →

LED POV Hard Drive Clock

October 17, 2008 by Caleb Kraft 29 Comments

[Ian Smith] sent us this POV display made from an old hard drive. It works by flashing some LEDs under the platter, which has a line cut in it. Since the platter spins at roughly 90 rotations per second, we perceive a solid image. He was inspired by [Alan Parekh]’s project, but did several things differently. Mounting the LEDs was much simpler in this project as he had a strip of RGB LEDs that came with adhesive tape on the back. He also used a small magnet and a hall effect sensor to measure full rotations instead of an IR beam sensor. Check the video after the break.

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Wireless Accelerometer Controlled RGB LED

October 9, 2008 by Caleb Kraft 10 Comments

[Andlier] sent us this cool little project. He has built a wireless accelerometer controlled RGB LED lighting system. Based on what a mouth full that is, it sounds complicated right? The end result looks fairly intuitive. Simply pick up the controller and tilt your hand to change the color of the light.

The controller consists of an Atmel AVR168 microcontroller. He doesn’t specify what transceiver he is using, but if you look in the comments, he notes that he added an antenna to it to extend the range. The part that controls the LED is based off of an Atmel AVR169 microcontroller hooked to some shiftbright LED modules.

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