easymidi example w/ Launchpad Mini MK3

index.js

const easyMidi = require("easymidi");

const launchpadInput = new easyMidi.Input(
  "Launchpad Mini MK3 LPMiniMK3 MIDI Out"
);

const launchpadOutput = new easyMidi.Output(
  "Launchpad Mini MK3 LPMiniMK3 MIDI In"
);

launchpadInput.on("noteon", function (msg) {
  console.log(msg);

  if (msg.velocity === 127) { // key is pressed down
    const color = Math.floor(Math.random() * 128);

    for (let i = 36; i < 100; i++) { // bottom left is note 36, top right is note 99
      setTimeout(() => {
        launchpadOutput.send("noteon", {
          note: i,
          velocity: color, // velocity for a MIDI out on the launchpad turns the key a specific color between 0 and 127. Color chart for newer Launchpads here: http://www.launchpadfun.com/downloads/Velocity-Colors_MASTER_PICTURE_hires.png
          channel: 0,
        });
      }, i * 10);
    }
  }
});