20pi

Multi MPU MIDI D Controller = MMMDC = 3600 = 20pi

This is a fork of this project.

      

| WARNING: DIY project. Use at your own risk!

Motivation

• The Teensy LC microcontroller is now deprecated. Alternatives suggested in the project github issues section (Teensy 4.0/4.1) are expensive.

Changes

The original footprint for all three PCBs has been slightly reduced for cost optimization.

Front Plate Changes

• Added a cutout to the front plate for the OLED display.

        

Back PCB Changes

• Complete redesign. It supports now either an ESP32 H2 DevKitM, a Raspberry Pico or a Waveshare Zero RP2040.

• It includes an optional front PCB daughterboard cutout that supports 4 rotary encoders and 4 addressable RGB leds using a GPIO expander. The front panel PCB has been enlarged accordingly to accomodate it.

• It connects to the back PCB using a header (I2C pins, Interruption, power,...)

• For the Raspberry Pico MCU, the PCB inclues traces for an optional USB-C connector. This connector and a couple of resistors are the only SMD parts, all the rest uses THT parts.

• Instead of 74hc4051 analog multiplexers with 8 channels, addon modules using the "denser" 74hc4061 variant with 16 channels have been used. They can be ordered for almost the same price as the 74hc4051, and can be directly soldered to the back PCB or mounted using "low profile" 3.5mm high sockets.

        

        

Front PCB Changes

• Almost no changes here: Only added header for I2C 0.91" OLED display to front PCB. It will show the last readout value + CC code sent. Example:

  OSC 2 Gain 89%
  MIDI CC 45

        

        

Case

• Included case to 3D print.

Original Project Documentation

The complete original README can be accessed here.