Milesight WS202: LoRaWAN PIR & Light Sensor

function decodeUplink(input) {
  var bytes = input.bytes;
  var data = {};

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

    // Device info (join / power-on): IPSO version, SN, hw/fw version, class
    if (channel === 0xff) { i += deviceInfoLen(type); continue; }

    if (channel === 0x01 && type === 0x75) {          // battery (%)
      data.battery = bytes[i]; i += 1;
    } else if (channel === 0x03 && type === 0x00) {   // PIR: 0 normal, 1 trigger
      data.pir = bytes[i] === 1 ? "trigger" : "normal"; i += 1;
    } else if (channel === 0x04 && type === 0x00) {   // daylight: 0 dim, 1 bright
      data.daylight = bytes[i] === 1 ? "bright" : "dim"; i += 1;
    } else {
      break;
    }
  }
  return { data: data };
}

function deviceInfoLen(type) {
  // 0xFF segment lengths from the published spec (skip device-info bytes)
  var map = { 0x01: 1, 0x08: 6, 0x09: 2, 0x0a: 2, 0x0b: 1, 0x0f: 1 };
  return map[type] || 1;
}