Hybrid MIDI Grand Piano

A hybrid piano translates traditional acoustic piano action into MIDI (unlike a purely digital MIDI keyboard), giving pianists the best of both worlds.

Greg Zweigle had long wanted to build his own, and has gotten all 88 keys working, using two Teensy 4.1s and a Kawai grand piano action.

Greg is working on several different architectures in parallel; while the aforementioned uses two Teensy 4.1s to handle all 88 keys, a higher-performance version uses two 4.1s for every eight keys plus two for a pedal unit (i.e. 24 for a complete piano).

The system measures and sends hammer velocity and optionally damper velocity over MIDI and can also output the data to optional Adafruit 2.8″ TFT touch screens. Schematics, firmware, documentation and more can be found in the project’s GitHub repo, and if you want to get really nerdy, Greg has published data from piano and piano action measurements in another repo. Much of the journey is also published on Greg’s YouTube channel, such as the latest progress below.