I've integrated an exercise from Automata into the second lab exercises (Digital and Analog Input). Here, I've hacked a servo (connected a cable to its potentiometer) to retrieve its spinning position. The excerpted code from Automata's class, allows to record its movement and reproduce it.

Physical computing exercise (Digital and Analog Inputs). Switch, led, potentiometer and servo

The entire project with instructions can be found in Adafruit's tutorial

Circuit's draw, excerpted from Adafruit's tutorial