So this horrid jumble of wires was one of my first attempts at developing the low level protocol.

At top right is a Teensy 2.0 acting as the master node, controlling a set of ATTINY2313 slave nodes. One has an IR motion sensor, and another has transistors switching red, green, blue, and white LEDs being used as place-holders for the high current LED drivers of a light fixture. The communication protocol has gone through several iterations since I wired up this hardware, so it's back to the drawing board now...