Thursday 19 March 2015

MIDI for the Arduino - Build a MIDI Output Circuit

Take Control

In this installment of the MIDI for the Arduino series, we are going to assemble a Midi Output Circuit and connect it to your Arduino UNO. This circuit is as easy as it gets.

Next we'll create a simple test program that will verify that everything is working. Download the file HERE.

If you're new to this series, check out the first article where we look at how a MIDI circuit works. This will help you understand what you are building here.

I am assembling the circuit on a small solder-less breadboard. The video will walk you through the steps of putting it together. Take your time and double check your work. Good luck!

The Arduino Midi Library can be downloaded HERE.

Schematic for the circuit.
MIDI Output Circuit


  1. Would a 1/4 watt 220 resistor work? I have those and they are a just a little smaller then what you show in the video. I'm guessing you used a 1/8 watt resistor.

    1. I actually did use a 1/4 watt resistor for this. Maybe I just have giant hands :)

    2. That's great news I'll give it a shot!

  2. i would really appreciate if you could upload the midi controller code for arduino mega 2560 as well.

  3. Hi, First of all thank you for such a solid tutorial.
    I built the circuit as described but for some reason it does not play any note.
    Two things which were net exactly as you said:
    1 - didn't have 220 resistor, so used 2x100 in series
    2 - MIDI jack I have is different from yours too, it is not 90 deg but straight, so I had to solder 3 wires to it to connect to the breadboard.
    Other that that everything else seems to be ok. The program uploaded into arduino no problem and the LED(13) is blinking as on your video.
    Could you please help

  4. How can i send midi output via Bluetooth? i want to build a foot controller for iOS

  5. Thanks for your tutorial . I tried this today but it doesn't work. Everything is the same: wiring, software ,Arduino version ecc.. The TX led and led13 led blink but nothing is sent .Any help?

  6. Can I get help on how to make a midi to USB using adruino for transfer of files from a computer to a Yamaha keyboard?
    The keyboard does not have a USB port but a midi port.

  7. Hi Dave, I understand that this simple circuit allows you to check if a note message is sent in (wrong?) To an external instrument (via the Midi in port, while the Arduino has a Midi out function), it is therefore exaggerated to think that this configuration ( including the sketch of course) can sysex messages be sent to an external tool?
    I ask because I would be interested in using the Arduino board in order to update a synthesizer via midi, but I imagine that without a skecth that implements information on sysex messages, this is not possible, or am I wrong.
    Thank you

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  9. Dear Nuts and Bolts. New to Arduino projects. Its fun! Q. My project dream is to convert my old Lowrey 1961 TUBE organ to self-play Midi files. Would you have a Schematics for wiring as well as some keyboard midi code so the midi music plays the right key notes on the Organ keyboard? I get all kinds of Youtubes showing how to play into the Virtual Organs/Pianos BUT almost few showing how to program the computer software to play an external instrument- like a 2-manual electric organ. From this I can expand to other parallel small rank of wood pipes. Please reply? ROSS