Cool midi project using PIC!
As you’ll see in the pictures, first I built a flat 8X8 array of switches laid out in the Hayden pattern (the white one plays “c”). The flat array let me lay the first one out pretty much just like the schematic diagram. It also let me not care too much about the end result, since I was learning to solder. The first version was wired to a breadboard, (not shown) where I debugged the circuitry. And after the electronics worked, I used it to develop the software.
The flexibility of this technology is part of the fun. It’s just buttons on a board, so you can build just about any shape you’d like to try. My son wants me to build another flat array, but complete with PIC & battery. His vision is, you hang it around your neck like sort of an electronic washboard. (“Bellyboard”) The range of a small electronic keyboard, the form-factor of a sandwich, and the ergonomics of scratching your stomach. With a sound module on your belt and headphones, just the thing for grooving in subway or hammock. Why not?
If you stare at Jordan Petkov’s schematics long enough, the following picture should make sense. The leads out the top were to the breadboard: 8 inputs to select a row, and 8 columns of outputs.
The MIDI controller electronics are mostly Jordan Petkov’s design. Jordan has done really great work on developing simple MIDI controllers using PIC “engines”; his site and offerings will reward your study. I added a power supply (7805-based), a MIDI OUT plug, and a 10MHz crystal rather than of the indicated 4MHz. The buttons are “Tactile Switches” (JameCo, 37 cents each), arranged on perfboard to mimic the Hayden diagrams.