Milesight VS133: AI ToF People Counting Sensor (LoRaWAN)

function decodeUplink(input) {
  var bytes = input.bytes;
  var data = { lines: {}, regions: {} };

  for (var i = 0; i < bytes.length; ) {
    var channel = bytes[i++];
    var type = bytes[i++];

    // Device info on join / power-on (0xFF segments)
    if (channel === 0xff) { i += deviceInfoLen(type); continue; }

    // Line counters: channels 03/06/09/0C = total IN, 04/07/0A/0D = total OUT.
    // Type 0xD2, value is UINT32 little-endian.
    if (type === 0xd2 && isLineIn(channel)) {
      line(data, lineIndex(channel, IN_BASE)).in = readUInt32LE(bytes, i);
      i += 4; continue;
    }
    if (type === 0xd2 && isLineOut(channel)) {
      line(data, lineIndex(channel, OUT_BASE)).out = readUInt32LE(bytes, i);
      i += 4; continue;
    }

    // Per-line period (channels 05/08/0B/0E, type 0xCC): in + out UINT16 LE.
    if (type === 0xcc && isLinePeriod(channel)) {
      var ln = line(data, lineIndex(channel, PERIOD_BASE));
      ln.period_in = readUInt16LE(bytes, i);
      ln.period_out = readUInt16LE(bytes, i + 2);
      i += 4; continue;
    }

    // Region headcount (channel 0F, type 0xE3): four UINT8 region counts.
    if (channel === 0x0f && type === 0xe3) {
      for (var r = 0; r < 4; r++) region(data, r + 1).count = bytes[i + r];
      i += 4; continue;
    }

    // Region dwell (channel 10, type 0xE4): region id + avg + max (UINT16 LE).
    if (channel === 0x10 && type === 0xe4) {
      var rg = region(data, bytes[i]);
      rg.avg_dwell = readUInt16LE(bytes, i + 1);
      rg.max_dwell = readUInt16LE(bytes, i + 3);
      i += 5; continue;
    }

    // Occlusion / lens-blocked alarm (channel 50, type 0xFC).
    if (channel === 0x50 && type === 0xfc) {
      data.occlusion_alarm = bytes[i + 2];
      i += 3; continue;
    }

    // Unknown channel: stop. Region/child layout is deployment-specific.
    break;
  }
  return { data: data };
}

var IN_BASE = 0x03, OUT_BASE = 0x04, PERIOD_BASE = 0x05;
function isLineIn(c)     { return c === 0x03 || c === 0x06 || c === 0x09 || c === 0x0c; }
function isLineOut(c)    { return c === 0x04 || c === 0x07 || c === 0x0a || c === 0x0d; }
function isLinePeriod(c) { return c === 0x05 || c === 0x08 || c === 0x0b || c === 0x0e; }
function lineIndex(c, base) { return (c - base) / 3 + 1; }

function line(data, n) {
  var key = "line_" + n;
  if (!data.lines[key]) data.lines[key] = {};
  return data.lines[key];
}
function region(data, n) {
  var key = "region_" + n;
  if (!data.regions[key]) data.regions[key] = {};
  return data.regions[key];
}
function readUInt16LE(b, i) { return (b[i + 1] << 8) | b[i]; }
function readUInt32LE(b, i) {
  return ((b[i + 3] << 24) | (b[i + 2] << 16) | (b[i + 1] << 8) | b[i]) >>> 0;
}
function deviceInfoLen(type) {
  // 0xFF segment lengths are firmware-specific (version, SN, downlink ACKs).
  void type; return 1;
}