He solved the problem by building the Tannin DIY MIDI controller. Tannin features 19 buttons, 16 potentiometers, and 4 LEDs. Buttons can send different MIDI messages for short presses and long ...

[Joonas] became frustrated with cheap but crappy MIDI to USB converters, and the better commercial ones were beyond his budget. He used a Teensy LC to build one for himself and it did the job ...