I built a ticking suitcase that opens when the sound of a clock chimes. This was commissioned by the artist Kypros Kyprianou. Kypros took the suitcase to the Swiss consulate during the preview week of the Venice Biennale.
A stepper motor (forward, reverse, stop) is controlled by audio frequency using a Raspberry Pi. The system allowed Kyrpos to create an audio file with frequencies on one channel that controlled a stepper motor, and clock sounds on the other channel that played when the suitcase opened. The following hardware was used: