Hi Electronics4you. I have a complete circuit of a simple touch-sensitive midi keyboard scanner buried somewhere in my boxes of paperwork. Many centuries back, a technician friend gave me a hand-drawn sketch that he had made (built his own). When I dig this sketch out, I'll draw it neatly in CAD, then submit it to the forum. Still have to learn how to safely attach an image and other media - my antivirus by default blocks visitors trying to access my hard-disk content. Maybe staff members can advise? Expect few days to about 1 week for Midi circuit. Cheers.