PJRC forum member pgi has created an impressive Teensy LC-based MIDI foot switch controller named BigFoot.

The elegant stacked-PCB system features eight assignable footswitches, bank selection, two expression pedal connectors with TRS/RTS switch, USB MIDI in/out, and MIDI DIN out.

Plan is to later build a full enclosure that will strengthen the structure.

Source code, schematics and BOM can be found on GitHub.