The OLED screen and four quad rotary encoder breakouts are daisy chained together with STEMMA QT cables. These boards are plugged into the STEMMA QT port on the Feather RP2040.

The Fritzing diagram has the I2C addresses for each quad rotary encoder breakout listed and the Soldering page in this guide walks through which jumpers need to be adjusted for each breakout.

The Feather and MIDI FeatherWing are plugged into a FeatherWing Doubler.

The code uses interrupts from the quad rotary encoder breakouts to determine if a button has been pressed or if a rotary encoder has been moved. The INT pins on the breakouts are soldered to digital inputs on the Feather RP2040.

• Breakout 0x49 INT to Feather D5 (green wire)
• Breakout 0x4A INT to Feather D6 (grey wire)
• Breakout 0x4B INT to Feather D9 (white wire)
• Breakout 0x4C INT to Feather D10 (orange wire)