This repository contains some documentation for building the ultrasonic keyboard. We'll walk through putting the hardware together first, then running the software. Once you complete those steps, you're basically done! There are some additional exercises in the Operate section where we play around with what we built.
The main repository that contains all the project files can be found here.
For reference, here's the header section of the README of that repository
Ultrasonic Keyboard is an electronics project that uses an Arduino (Nano), an ultrasonic sensor, and a piezobuzzer to create a mock piano keyboard that plays tones using distance readings from the sensor. The idea takes inspiration from the theremin.
This project is not intended to be used functionally. Instead, it is meant to serve as a basic introduction to working with microcontrollers, circuitry, and digital audio.