Using Arduino photocell sensor (input) and piezo sensor (output) to create a theremin

The goal of this lab was to use piezo speakers to output sound. A piezo is an electronic device that generates a voltage when it’s physically deformed by vibration, sound wave, or mechanical strain. Similarly, when you put a voltage across a piezo, it vibrates and creates a tone. Piezos can be used both to play tones and to detect tones.

For this lab, we first explored the piezo sensor by creating melody using musical notes and using a photocell sensor to create a theremin. A theremin is a musical instrument that is played without touching. In this case, we used a photocell to used to detect movement by blocking some light and output sound through the piezo.