Milesight EM500-PT100: LoRaWAN Industrial Temperature 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++];

    if (channel === 0x01 && type === 0x75) {          // battery (%)
      data.battery = bytes[i]; i += 1;
    } else if (channel === 0x03 && type === 0x67) {   // temperature (°C)
      data.temperature = readInt16LE(bytes, i) / 10; i += 2;
    } else if (channel === 0x83 && type === 0xd7) {   // temperature + alarm
      data.temperature = readInt16LE(bytes, i) / 10;
      data.temperature_mutation = readInt16LE(bytes, i + 2) / 10;
      data.temperature_alarm = readAlarm(bytes[i + 4]);
      i += 5;
    } else {
      break;
    }
  }
  return { data: data };
}

function readInt16LE(b, i) {
  var v = (b[i + 1] << 8) | b[i];
  return v > 0x7fff ? v - 0x10000 : v;
}

function readAlarm(b) {
  var map = { 0: "threshold alarm", 1: "threshold alarm release", 2: "mutation alarm" };
  return map[b] !== undefined ? map[b] : "unknown";
}