Ability to use media keys with Pico over USB HID

Here's the latest incarnation! Working pretty well.

Sometimes the mute and playpause commands don't work the 2nd time you press them, but with subsequent presses work fine

let debug = 0;
let code = 0;
let timeout;
let lastTime;

const VOLUME_UP    = 16712445;
const VOLUME_DOWN  = 16750695;
const PLAY_PAUSE   = 16754775;
const MUTE         = 16720605;
const NEXT         = 16748655;
const PREV         = 16769055;
const STOP         = 16756815;

E.setUSBHID({
  reportDescriptor : [
  0x05, 0x0c,                    // USAGE_PAGE (Consumer Devices)
  0x09, 0x01,                    // USAGE (Consumer Control)
  0xa1, 0x01,                    // COLLECTION (Application)
                                 // -------------------- common global items
  0x15, 0x00,                    //   LOGICAL_MINIMUM (0)
  0x25, 0x01,                    //   LOGICAL_MAXIMUM (1)
  0x75, 0x01,                    //   REPORT_SIZE (1)    - each field occupies 1 bit
                                 // -------------------- misc bits
  0x95, 0x05,                    //   REPORT_COUNT (5)
  0x09, 0xb5,                    //   USAGE (Scan Next Track)
  0x09, 0xb6,                    //   USAGE (Scan Previous Track)
  0x09, 0xb7,                    //   USAGE (Stop)
  0x09, 0xcd,                    //   USAGE (Play/Pause)
  0x09, 0xe2,                    //   USAGE (Mute)
  0x81, 0x06,                    //   INPUT (Data,Var,Rel)  - relative inputs
                                 // -------------------- volume up/down bits
  0x95, 0x02,                    //   REPORT_COUNT (2)
  0x09, 0xe9,                    //   USAGE (Volume Up)
  0x09, 0xea,                    //   USAGE (Volume Down)
  0x81, 0x02,                    //   INPUT (Data,Var,Abs)  - absolute inputs
                                 // -------------------- padding bit
  0x95, 0x01,                    //   REPORT_COUNT (1)
  0x81, 0x01,                    //   INPUT (Cnst,Ary,Abs)
  0xc0                           // END_COLLECTION
  ]
});

function p(c, cb) {
  E.sendUSBHID([c]);
  return cb();
}

next = function (cb) {
  p(0x1, cb);
  console.log('next');
};
prev = function (cb) {
  p(0x2, cb);
  console.log('prev');
};
stop = function (cb) {
  p(0x4, cb);
  console.log('stop');
};
playpause = function (cb) {
  p(0x8, cb);
  console.log('playpause');
};
mute = function (cb) {
  p(0x10, cb);
  console.log('mute');
};
volumeUp = function (cb) {
  p(0x20, cb);
  console.log('volumeUp');
};
volumeDown = function (cb) {
  p(0x40, cb);
  console.log('volumeDown');
};

const cb = () => {};

function handleCode() {
  timeout = undefined;
  if (debug) print(code);
  LED2.write(true);

  if (code === PLAY_PAUSE)  playpause(cb);
  if (code === VOLUME_UP)   volumeUp(cb);
  if (code === VOLUME_DOWN) volumeDown(cb);
  if (code === MUTE)        mute(cb);
  if (code === NEXT)        next(cb);
  if (code === PREV)        prev(cb);
  if (code === STOP)        stop(cb);

  code = 0;
  LED2.write(false);
}

// When an IR pulse is detected
function onPulseOn(e) {
  code = (code * 2) | (e.time - lastTime > 0.0008);
  if (timeout !== undefined) clearTimeout(timeout);
  timeout = setTimeout(handleCode, 20);
  lastTime = e.time;
}

// When IR pulse stops
function onPulseOff(e) {
  lastTime = e.time;
}

setWatch(onPulseOff, A5, { repeat: true, edge: "rising" });
setWatch(onPulseOn, A5, { repeat: true, edge: "falling" });

setWatch(
  // Press the button on the pico to enable debug mode and
  // see the IR code for your own remote
  function (e) {
    debug = !debug;
    console.log(`Debug mode ${debug ? "on" : "off"}`);
  },
  BTN,
  { repeat: true }
);