Plays a single note from a midi serial input. Currently working on a version for boards that have 3 or more timers.
You will need Hairless MIDI<->Serial Bridge. Once downloaded and installed, change the MIDI IN option to your midi output device. It should look like something like this.
If one isn't listed, use loopMIDI. Open loopMIDI and click on the plus sign. Select that midi port you just created, and select it in Hairless MIDI<->Serial Bridge's MIDI In dropdown. You can now select that output port in your midi software. (If you don't have one, go to Signal, click on Settings, and then midi. Now select the output device you created, and click Ok. You can open midis with the File dropdown. Click the play button to start playback.)
Connect one of the speaker pins to pin 3 (default), connect the other pin to GND.
Copy and paste the contents of the index.ino file into Arduino IDE. Remember to download the midi library using the arduino libraries tab.
Changing the midi input channel:
Find the line #define MIDITRK 1 and change the number 1, to your desired midi channel. (1-16)
Changing the audio out pin:
Find the line #define speakerPin 3 and change the three to your desired output pin, that supports pwm.
Changing the LED Status Pin
Find the line define ledPin 13 and change the thirten to your desired output pin. (Pin 13 is equal to LED_BUILTIN)
Feel free to ask me!