USBMIDI-Adapter.ino

USBMIDI-Adapter

Turns an Arduino into a USB to 5-pin DIN MIDI adapter.

Boards: 🛈

AVR USB, Due, Nano 33 IoT, Nano 33 BLE, Pi Pico, ESP32-S3, Teensy 3.x

Connections

• TXD: connected to a MIDI 5-pin DIN output connector (with series resistor, possibly through a buffer)
• RXD: connected to a MIDI 5-pin DIN input connector (with an optocoupler)

See https://midi.org/specifications/midi-transports-specifications/5-pin-din-electrical-specs for the schematic, optocoupler models and resistor values.

Behavior

• The Arduino will show up as a USB MIDI device.
• Any MIDI messages sent to the Arduino over USB are sent out to the 5-pin DIN output connector.
• Any MIDI messages sent to the Arduino through the 5-pin DIN input connector are sent over USB.

See also

MIDI over USB

MIDI Tutorial

Written by PieterP, 2024-01-21
https://github.com/tttapa/Control-Surface

 
#include <Control_Surface.h>
 
// Instantiate a MIDI over USB interface
USBMIDI_Interface midi_usb;
// Instantiate a 5-pin DIN MIDI interface (on the TX and RX pins of Serial1)
HardwareSerialMIDI_Interface midi_ser {Serial1};
// Instantiate the pipe to connect the two interfaces
BidirectionalMIDI_Pipe pipes;
 
void setup() {
  // Manually route MIDI input from the serial interface to the USB interface,
  // and the MIDI input from the USB interface to the serial interface
  midi_ser | pipes | midi_usb;
  // Initialize the MIDI interfaces
  MIDI_Interface::beginAll();
}
 
void loop() {
  // Continuously poll all interfaces and route the traffic between them
  MIDI_Interface::updateAll();
}