Puck MIDI Note On

You don't have to touch the module itself. Try:

var midi = require("ble_midi");
midi.init();

midi.noteOn = function(channel, controller, value) {
  NRF.updateServices({
    "03B80E5A-EDE8-4B33-A751-6CE34EC4C700": { // MIDI
      "7772E5DB-3868-4112-A1A9-F2669D106BF3": {
        value: [0x80, 0x80, 0x90 + channel, controller, value],
        notify: true
      }
    }
  });

setWatch(function() {
  // When a button is pressed...
  digitalPulse(LED,1,10);


  midi.noteOn(0, 60, 100);
}, BTN, { repeat:true, edge:"rising", debounce:10 });

If this works, let me know and I can add it to the module properly.