Avalanche a la Ikea

It was some stuff I saw in Ikea in France (means 8-10 years ago). It was a board, with bi-color red-blue leds array quite big, inside a semi-opaque white frame, and some leds were turning slowly on or off one by one, somewhere like in the game of life ... but quite slow. I found it so cool and wanted one but never made the step. Now I'm a full grown geek and I can make my own :P

This project will use the RGBoard, which is in fact the main raison d'etre of the board. The board is poorly designed, with big flaws but after a few acrobatic soldering it can do the job.

• PWM is done with a TLC5940 that drives the 8 ground pins (8 columns of led)
• On/off is done by 3x 74HC595 in serial, each driving 8 rows, one SIPO per color

Technical links

• Using 74HC595 to make extra IO http://www.arduino.cc/en/Tutorial/ShiftOut
• Doing soft PWM with shift registers http://www.elcojacobs.com/shiftpwm/
  • Didn't use it, used a TLC5940 for the PWM. The shift registers are used but just to add extra IO pins
• Using the TLC5940 (expensive)
  • Expensive, rare (ebay or digikey), current sink only ... If you can avoid it I recommend.

The assembled version with a 10x10cm diffraction plastic layer	On the left: the green board with a Atmega 328 and a TLC5940 10 bits PWM controlling the GND of the leds On the right: the white board with 3x SIPO 8bits registers 74HC595 in serial, one for each color
The wiring mess, with acrobatic soldering and lots and lots of glue to keep everything together.	The led solder face. On purpose some leds are not present to not have a regular pattern. And save cash.