AppleMIDI (aka rtpMIDI) for Arduino

arduino-library-badge Build Status License: CC BY-SA 4.0

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

Important: Please read the note below on enlarging the standard Ethernet library buffersize to avoid dropping MIDI messages!


  • Build on top of the popular FortySevenEffects MIDI library
  • Tested with AppleMIDI on Mac OS (Big Sur) 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)

New in 3.0.0

  • Bug Fixes (long session names get cropped)
  • Reduced memory footprint (see AVR_MinMemUsage example and note below)
  • Extended and revised callbacks to receive AppleMIDI protocol feedback (see AVR_Callbacks example)
  • Who may connect to me (Directory) (see AVR_Directory example)

    New in 3.1.0

  • Increased stability in high-throughput situations
  • Updated wiki

    New in 3.1.1 and 3.1.2

  • Bug fixes en enhancements


From the Arduino IDE Library Manager, search for AppleMIDI


This will also install FortySevenEffects MIDI library

Basic Usage

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

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };


void setup()

  MIDI.begin(); // listens on channel 1

void loop()
  // Listen to incoming notes;

  if (something) {
    // Send MIDI note 40 on, velocity 55 on channel 1
    MIDI.sendNoteOn(40, 55, 1);

More usages in the examples folder and in the wiki


  • Arduino/Genuino (Mega, Uno, Arduino Ethernet, MKRZERO, ...)
  • ESP8266 (Adafruit HUZZAH ESP8266, Sparkfun ESP8266 Thing Dev)
  • ESP32 (Adafruit HUZZAH32 – ESP32 Feather Board) Wi-Fi
  • ESP32 with W5500 Setup
  • Teensy 3.2 & 4.1
  • Adafruit Feather M0 WiFi - ATSAMD21 + ATWINC1500

Network Shields

  • Arduino Ethernet shield (Wiznet W5100 and W5500)
  • Arduino Wifi R3 shield
  • MKR ETH shield (W5500 and W6100 based)
  • Teensy WIZ820io W5200
  • Teensy 4.1 with Ethernet Kit


Session names

Session names can get really long on Macs (eg 'Macbook Pro of Johann Gambolputty .. von Hautkopft of Ulm') and will be truncated to the MaxSessionNameLen

Memory footprint

The memory footprint of the library can be lowered significantly, read the wiki

Ethernet buffer size

It's highly recommended to modify the Ethernet library or use the Ethernet3 library to avoid buffer overruns - learn more


Use wired Ethernet to reduce latency, Wi-Fi increases latency and latency varies. More of the wiki

Arduino IDE (

  • 1.8.16


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.

Arduino Applemidi Library

Send and receive MIDI messages over Ethernet (rtpMIDI or AppleMIDI)

Arduino Applemidi Library Info

⭐ Stars 210
🔗 Source Code
🕒 Last Update 8 months ago
🕒 Created 9 years ago
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😎 Author lathoub