The following description will work with Atmega32U4 Arduino Boards.
TOOLCHAIN
- download the arduino ide: www.arduino.cc
- install the arduino ide
- install the MIDIUSB library: Sketch -> Include Library -> Library Manager… -> search for “MIDIUSB” -> install
- load the midi example to the arduino board: File -> Examples -> MIDIUSB -> MIDIUSB_write -> upload
- open your favourite midi software and choose arduino as midi input
- now you should get midi events every second
MIDI BASICS
- 3 byte message
- 4 byte if you are using USB
standard MIDI message:
- 1st byte: message type (0..7) and channel (0..15)
- 2nd byte: id (0..127)
- 3rd byte: value (0..127)
most used message types (www.midi.org -> specs -> midi reference tables -> summary of midi messages):
- 0x08: note off
- 0x09: note on
- 0x0B: control change (cc)
example messages:
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midiEventPacket_t noteOn = { 0x09, 0x90, pitch, velocity }; midiEventPacket_t noteOn = { 0x09, 0x90 | channel, pitch, velocity }; midiEventPacket_t noteOn = { 0x09, 0x90, 60, 127 }; midiEventPacket_t noteOff = { 0x08, 0x80, pitch, velocity }; midiEventPacket_t midiCc = { 0x0B, 0xB0, 0, 62 }; |
First example – Button
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/* send midi note on/off when button is pressed on Pin 2 */ #include "MIDIUSB.h" void setup() { pinMode(2, INPUT_PULLUP); } void loop() { if( digitalRead(2) == false ) { // note on midiEventPacket_t noteOn = {0x09, 0x90, 60, 100}; MidiUSB.sendMIDI(noteOn); MidiUSB.flush(); delay(500); // note off midiEventPacket_t noteOff = {0x09, 0x90, 0, 0}; MidiUSB.sendMIDI(noteOff); MidiUSB.flush(); delay(500); } } |
EXAMPle 2 – KEYBOARD
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/* send note on when button is pressed and note off when button is released */ #include "MIDIUSB.h" bool oldButtonState = false; bool newButtonState = false; void setup( { pinMode(2, INPUT_PULLUP); } void loop() { newButtonState = digitalRead(2); if( newButtonState != oldButtonState ) { if( newButtonState == false ) { midiEventPacket_t noteOn = {0x09, 0x90, 60, 100}; MidiUSB.sendMIDI(noteOn); MidiUSB.flush(); } else { midiEventPacket_t noteOff = {0x09, 0x90, 0, 0}; MidiUSB.sendMIDI(noteOff); MidiUSB.flush(); } oldButtonState = newButtonState; delay(25); } } |
EXAMPle 3 – ANALOG I
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/* example 3: send analog value every second */ #include "MIDIUSB.h" void setup() {} void loop() { uint16_t analogValue = analogRead(A0); uint8_t analogSend = analogValue >> 3; midiEventPacket_t midiCc = { 0x0B, 0xB0, 0, analogSend }; MidiUSB.sendMIDI(midiCc); MidiUSB.flush(); delay(1000); } |
example 4 – Analog II
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/* send value when analog value changes*/ #include "MIDIUSB.h" uint8_t oldAnalogValue = 0; uint8_t newAnalogValue = 0; void setup() {} void loop() { uint16_t analogValue = analogRead(A0); uint8_t newAnalogValue = analogValue >> 3; if( newAnalogValue != oldAnalogValue ) { midiEventPacket_t midiCc = { 0x0B, 0xB0, 0, newAnalogValue }; MidiUSB.sendMIDI(midiCc); MidiUSB.flush(); oldAnalogValue = newAnalogValue; } } |
