"Trembling Cricket" Firefighter
This guy is the evolution of the original Gamadome that I built with Fred Martin, as a first attempt at using the Gamoto motor controller with a Handy Cricket. That was in 2002. Then for the 2004 contest, we gave it to one of Fred's students, and he made some major improvements and ended up taking 3rd place!
It's a basic three-layer disk design, with the battery on the bottom, motors on the next level, then motor controllers, and finally the cricket on top. It uses a Sharp IR sensor to follow the right wall, and photocells to track the flame.
It actually has two crickets controlling the motion. We wanted to see if we could design a cooperative system where two crickets passed control back and forth. One of the crickets does nothing but follow the wall, and check for the presence of a flame, either in front or off to the left (to try to catch that elusive candle in the island room). When a flame is detected, using an IR signal, control is passed to the other cricket. The second cricket then tracks the flame, and when it's close enough, turns on the fan to put it out.
The student wrote a clever routine to then return home without entering any other rooms. I think it has to do with checking the length of the hallway up ahead, to determine where it is, and when to turn.