MatrixRat

Neotrellis needs +5v for Vin. Onboard I2C level shifter is set for 3.3v by default.

For the PCB, Adafruit Product ID 3954, and the Silicone elastomer 4x4 button keypad Product ID 1611. A couple of strategically placed elastic bands can be used to to strap the two parts together for experimentation. If you want to play with 8x8...

The Neotrellis library code is blocking and depending on what you may be trying to do, painfully slow and is probably the culprit messing up audio. My Midi controller project has an ILI9341 screen, 18 encoders and two hardware buttons wired to a...

Double check solder bridge on address select pads, the pic is unclear. Try inserting 150R in SCL and SDA lines as close as possible to T4.1 SCL and SDA pins.

You need to call read to get some action. void loop() { usbMIDI.read(); }