How to Build an Open Source MIDI Keyboard

This project details the steps to build your own Open Source (musical) keyboard which connects to a computer via USB and sends MIDI signals. This is achieved using an AN2131 development board. The AN2131 is now discontinued, so development boards can be bought cheaply on eBay. Alternatively you could use another USB microcontroller, if you are able to port the firmware. You could also hack any EZ-USB based device, of which there are many.

I wont be going into details of constructing a microcontroller board, as this has been covered many times before. I also wont cover constructing the physical mechanisms, instead using a cheap toy keyboard to demonstrate the idea, electronics and firmware.

Through out this write up you can click on the pictures to see a bigger version.

The text and images of this series of articles are Copyright (c) Alistair Buxton 2006.


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alternative Midi keyboard

The standard PS2 keyboard for the PC makes a good, abet non-traditional, MIDI input keyboard. Download full details from the file:
located at:

Feel Free to download any or all of the guitar effect schematics there also.