The system consists of a hall effect sensor at the pedals to measure cadence, an Arduino controller, and a servo mechanism to replace the manual shifter.

This post discusses how I integrated a regular microphone into an Arduino setup for some serious audio experiments. I used a prewired module which holds a MAX9814 single chip microphone amplifier with ...

However, control theory shows up in a surprising number of places from filters to oscillators, to the automatic gain control in a receiver.