The denizens of the diykeyboard mailinglist are actively designing a collection of Open Hardware designs for people to build their own instruments. We'd like to invite you to participate!
We're hoping to make the designs as generic as possible so they can be used by as many people as possible. Please contribute your requirements and "blue-sky ideas" to this section for the hardware and software gurus to attempt to include.
Some of us have built keyboards based around common PC keyswitches such as the MX1A range from Cherry. Others have been exploring other input methods such as two axis joysticks to provide additional axes of control. Control hardware designs live here.
There are several different approaches one can take to make sense of the keyboard data:
1) USB <-> SPI bridge. This would mean all the key scanning software would be implemented on the PC.
2) Propeller Based: A parallax propeller based design which uses the 8 core multiprocessor to both scan, process and emit MIDI events.
3) Arduino Based: A proposed design which would use the Arduino platform to scan, process and emit MIDI events.
4) MIDIBox Based: midibox is an existing open source project which provides generic input -> midi event system design.