Ultrasonic Pi Piano (2017)
The Ultrasonic Pi Piano is a piano that uses ultrasonic sensors as inputs and translates the distances into MIDI notes that are then played via a software synthesizer on the Raspberry Pi.
This project has been featured on hackaday.io, Adafruit Blog, and The Raspberry Pi Foundation’s Blog.
Here’s a video showing the final product.
Here’s a video that shows how the project works.
Source code and documentation is available at https://github.com/andygrove/ultrasonic-pi-piano.