Uses simple sensor-driven reflexes, and PID loop for motor speed control and stall detection. Work is on-going with the firmware. The charging circuit is built into the robot. I thought it would be a great way to combine my talents and skills into a single hobby. I started out with many prototyped circuits and attempted modifying hobby servos, since nice gear motors were hard to find, not to mention all of the axles, shaft couplers, and other mechanical goodies needed in order to attach wheels to the motors.
Hobby servos are cheap and easily modified.
As you can see, this beast would shatter in a million pieces if it fell to the floor. I have learned an awful lot from this initial attempt at robot building and hope to have a better start, mechanically anyway, on the next robot. There are no high-level behaviors programmed at all yet, although I do plan to spend some time on that part while starting the mechanics and base of my next robot. Surprisingly, complex behaviors do appear to manifest as emergent properties of these simple reflexes. I think the cat knows the robot is no threat because she just sits and watches it.