OkÖ. This was a big deal for me. For some reason it took me a while to get a TWI (I2c) interface up and running properly and it held me up from doing some blog posts. But itís working now! Here I have two simple avr platforms up and running. The one on the left is the master and the one on the right is the slave. To control 300-500 LED lights I decided that it was a job for more then one microcontroller. So I will have a master LED controller and several slave LED controllers. The master will push the animation frames down the bus and each of the slave controllers will control a bank of shift registers connected to 64 LEDS.
Here is a close up of the Master Controller. Not really much different circuitry then before. I will be posting the code up here eventually. That is where most of the fun is! Donít be fooled by the connector up to the top left. Itís not Ethernet. Thatís actually a serial connection to my computer for debugging. I use Ethernet patch cables instead of serial cables often now because I can make my own cables then. Just slap a couple of custom RJ45-DSUB-9 adapters onto an ether cable and you have a serial cable. I picked that up from Make Magazine (Issue 01). Pretty Handy.
Itís great to be a geek!