Have a look at this fun project called the Shy Light. The light doesn’t like to be seen in public and uses a basket to hide in. X10 and two microcontrollers are being used to get the job done.
“Why TWO Microcontrollers? The Dual-Microcontroller Circuit: Master (right) Slave (left) The Master Control microcontroller handles the foot-switch input, orchestrates the timing of the opening/closing of the basket (using commands to the Slave Control unit) and the lamp dimming. Initially, I had no idea that the project would require two; there are enough analog and digital pins on one microcontroller to do it all, but—and I’m not absolutely certain about this because I didn’t keep detailed notes about this—I think that I was forced into a dual processor arrangement because of the complexity of the program timing. As I designed the circuit, I came to the realization that the timing required by the various elements was going to be difficult for me to accomplish as an amateur C-coder if I tried to stuff it all into one controller. So I don’t want to say that “it can’t be done with one chipâ€. I just decided that it was simpler for me to compartmentalize the various tasks with hardware. So I added another ATMEGA168, at an added cost of about $5.00.”