Minimoog Keyboard

Not much activity on the ORT at the moment as I am attempting to finish off the Minimoog. As I noted in a previous post the Keyboard for the Minimoog got effectively destroyed when it was filled with rainwater. The actual mechanisim that was used in the Mini was manufactured by a company called Kimber-Allen, who I believe are not in bussiness any more. The actual design is really very complicated. The actual up/down keystroke movement is transfered through a lot of springs and small arms to move a rather wobbly mechanisim with two gold plated springs upon it. These springs in turn provided the key information and the gate information. Rather than spend a LOT of time rebuilding all of this and probably ending up with a sub-optimal design I decided to find a replacement keyboard. A late 70's Italian Organ proved to be prefect. It was very cheap, the key mechanisim was simple and easy to adapt, the keys looked a little yellow and discoloured so that they looked about the same vintage as the rest of the unit. Each key has single contect and all the keys are tied togther with a diode ORing scheme. I obviously couldn't use the existing method of a voltage divider that was used in the old keyboard. I didn't really want to do that anyway as I wanted a MIDI feed out from the keyboard to control other stuff anyway and it didn't really seem sensible to take a digital signal into the analog domain then back again. I then decided to split the whole thing between two microcontrollers. One in the keyboard that just scanned the keys and sent the information serially to another micrcontroller inside the electronics unit of the Minimoog. I used the AVR microcontroller as it is cheap, easily available, powerful and well supported with various software tools.