Open Piano Teacher is a very simply but very powerful system, which can help you to learn piano yourself, without any knowledge in theory of music.
The principle is “follow the red light”.
It means that, in this system, a strip of leds takes place behind each key.
A computer is linked with an arduino uno. On the computer, a midi software player sends the notes to the arduino through the usb link. When you play a midi song, the arduino decodes the midi stream, and turn on the correct light.