MAKE group member Leevonk has a great Instructable on franken-modding a Furby… he writes -
“I took control of a furby’s body using a PIC16F877 microcomputer. Videos on last step.
The furby’s in-built sensors and actuators:
light sensor, IR sensor, IR transmitter, tongue touch sensor, belly touch sensor, microphone, speaker.
The furby’s main (and only) motor was dead, so I added other motors.” – Link.