(1) I think your options for something that specific are likely either custom sheet metal, or custom (ply)wood.
(2) A single Teensy 4 at 600 MHz will have vastly more than enough horsepower to spare to scan three keyboards and drive 3 MIDI outs by bitbanging.
The Teensy 4 also has a ton of GPIO pins. If it's not enough for 3 keyboards, you can create a PCB (or a breadboard solution) with one or more PCF8574 bus expanders daisy chained on an I2C bus to access more GPIO.
(2) A single Teensy 4 at 600 MHz will have vastly more than enough horsepower to spare to scan three keyboards and drive 3 MIDI outs by bitbanging.
The Teensy 4 also has a ton of GPIO pins. If it's not enough for 3 keyboards, you can create a PCB (or a breadboard solution) with one or more PCF8574 bus expanders daisy chained on an I2C bus to access more GPIO.
Statistics: Posted by kimballa — Thu Oct 03, 2024 9:04 pm