This project is a reimplementation of a cheap Midi keyboard's processor board using an Arduino.
Because I bought a cheap Midi keyboard, and the software was terrible, and the incorrect version for the keyboard I bought.
I couldn't find a way to reprogram it, so I ripped the hardware out and, as Zaphod Beeblebrox would say, gave it a reprogramming it would never forget.
If you are making your own Midi keyboard, or you're in a similar position to the above, you might find this useful, or indeed fun.
If you want further details of the project, it's on my blog, here: https://piecesofpi.co.uk/arduino-hacking-cheap-midi-keyboard-1/