AppleMIDI (aka rtpMIDI) for Arduino

Enables an Arduino with IP/UDP capabilities (Ethernet shield, ESP8266, ESP32, ...) to particpate in an AppleMIDI session.

Features

• Build on top of the popular FortySevenEffects MIDI library
• Tested with AppleMIDI on Mac OS (Catalina) and using rtpMIDI from Tobias Erichsen on Windows 10
• Send and receive all MIDI messages
• Uses callbacks to receive MIDI commands (no need for polling)
• Automatic instantiation of AppleMIDI object (see at the end of 'AppleMidi.h')
• Compiles on Arduino, MacOS (XCode) and Windows (MSVS)

Installation

From the Arduino IDE Library Manager, search for AppleMIDI

This will also install FortySevenEffects MIDI library

Basic Usage

#include <Ethernet.h>
#include <AppleMIDI.h>

APPLEMIDI_CREATE_DEFAULTSESSION_INSTANCE(); 

void setup()
{
  MIDI.begin();
  
  // Optional
  AppleMIDI.setHandleConnected(OnAppleMidiConnected);
}

void loop()
{
  // Listen to incoming notes
  MIDI.read();
  
  // Send MIDI note 40 on, velocity 55 on channel 1
  MIDI.sendNoteOn(40, 55, 1);
}

void OnAppleMidiConnected(uint32_t ssrc, const char* name) {
}

APPLEMIDI_CREATE_DEFAULTSESSION_INSTANCE(); creates 2 instance: MIDI and AppleMIDI. MIDI is the instance that manages all MIDI interaction, AppleMIDI is the instance this manages the rtp transport layer.

More usages in the examples folder

Hardware

• Arduino/Genuino (Mega, Uno, Arduino Ethernet, MKRZERO, ...)
• ESP8266 (Adafruit HUZZAH ESP8266, Sparkfun ESP8266 Thing Dev)
• ESP32 (Adafruit HUZZAH32 – ESP32 Feather Board)
• Teensy 3.2
• Adafruit Feather M0 WiFi - ATSAMD21 + ATWINC1500

Memory usage

This library is not using any dynamic memory allocation methods - all buffers have a fixed size, set in the AppleMIDI_Settings.h file, avoiding potential memory leaks and memory fragmentation.

The minimum buffer size (MaxBufferSize) should be set to 64 bytes (also the default). Setting it to a higher value will make sending larger SysEx messages more efficiant (large SysEx messages are chopped in pieces, the larger the buffer, the less pieces needed), at the price of a bigger memory footprint.

MaxNumberOfParticipants is another way to cut memory - each particpants uses approx 300 bytes. Default number of participants is 1 (using 2 sockets). Beware: the number of sockets on the Arduino is limited. The W5100 support 4, the W5200 and W5500 based IP chips can use 8 sockets. (Each participant uses 2 sockets: port 5004 and 5004+1). (Base port can be set in APPLEMIDI_CREATE_DEFAULT_INSTANCE)

Network Shields

• Arduino Ethernet shield (Wiznet W5100 and W5500)
• Arduino Wifi R3 shield
• MKR ETH shield
• Teensy WIZ820io W5200

Arduino IDE (arduino.cc)

• 1.8.10

Contributing

I would love to include your enhancements or bug fixes! In lieu of a formal styleguide, please take care to maintain the existing coding style. Please test your code before sending a pull request. It would be very helpful if you include a detailed explanation of your changes in the pull request.