The Build Your Own Teensy MIDI Encoder Workshop will show you how to use a Teensy 3.1 to create a MIDI encoder that sends MIDI OUT messages over the Teensy's micro-B USB plug.
During the workshop, you will build a serial-to-parallel, parallel-to-serial switch matrix using a Teensy 3.1, a breadboard, IN4148 diodes, and reed switches (if you wish to validate the switch matrix). Darin will demonstrate how to write the switch matrix scan code and how to encode the simulated keypress signals into MIDI OUT messages using the Arduino/Teensy Keypad and MIDI libraries. Extending the code to accommodate MIDI IN, velocity sensitivity and other MIDI messages, as well as using shift registers (74HC595 and 74HC165), will be discussed.
Recommended hardware and software for the workshop: