New controller module coming along - managed to work out how to output Gate, Trigger, and Pitch from the Arduino via CV.
Need to build the actual switching interface, which might be the tricky bit with the physical controls, but have a couple of options for how to make that work.
Next thing to try and do is output an envelope shape too, mostly as I've got one free chanel of the DAC left over. Might be quite tricky to make it in code tho. I've been thinking about how to work it out mathematically, to get a curve that will work. Looking at y=1-√x and have an idea of how to implement it, but won't know till I've tried it.
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I was surprised looking at tutorials that anyone who's made a piano type keyboard for an Arduino just uses push buttons, one per digital input. This resistor array I'm using is a method I remembered seeing inside an old Farfisa organ I dismantled when I was a teenager. Seems much more versatile. You could quite easily tune this to play specific notes in a set scale, but I like the idea of just setting the top and bottom notes and dividing the frequencies evenly in between. Some weird scales you can reconfigure on the fly. Could always whack it into a pitch quanteiser if bothered about that sort of thing!
@grahamdunning I guess the resistor array only lets you press 1 key at a time?
@jarkman yes, monophony! It also defaults to the lowest note if more than one connection is made.