Milesight EM410-RDL: LoRaWAN Radar Distance & Level Sensor

function decodeUplink(input) {
  var bytes = input.bytes;
  var data = { events: [] };

  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 === 0x04 && type === 0x82) {   // distance (mm)
      data.distance = readInt16LE(bytes, i); i += 2;
    } else if (channel === 0x05 && type === 0x00) {   // position (0 normal / 1 tilt)
      data.position = bytes[i] === 0 ? "normal" : "tilt"; i += 1;
    } else if (channel === 0x06 && type === 0xc7) {   // radar signal RSSI
      data.radar_signal_rssi = readInt16LE(bytes, i) / 100; i += 2;
    } else if (channel === 0x84 && type === 0x82) {   // distance threshold alarm (2B distance + 1B status)
      var d = readInt16LE(bytes, i);
      data.distance = d;
      data.events.push({ distance: d, distance_alarm: readDistanceAlarm(bytes[i + 2]) });
      i += 3;
    } else if (channel === 0x94 && type === 0x82) {   // distance mutation alarm (2B distance + 2B mutation + 1B status)
      var dm = readInt16LE(bytes, i);
      data.distance = dm;
      data.events.push({
        distance: dm,
        distance_mutation: readInt16LE(bytes, i + 2),
        distance_alarm: readDistanceAlarm(bytes[i + 4])
      });
      i += 5;
    } else if (channel === 0xb4 && type === 0x82) {   // distance exception / blind-spot alarm (2B distance + 1B status)
      var raw = (bytes[i + 1] << 8) | bytes[i];
      var ev = { distance_exception: readDistanceException(bytes[i + 2]) };
      if (raw !== 0xfffd && raw !== 0xffff) { ev.distance = readInt16LE(bytes, i); }
      data.events.push(ev);
      i += 3;
    } else {
      break;
    }
  }
  if (data.events.length === 0) { delete data.events; }
  return { data: data };
}

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

function readDistanceAlarm(v) {
  if (v === 0) return "threshold alarm release";
  if (v === 1) return "threshold alarm";
  if (v === 2) return "mutation alarm";
  return "alarm " + v;
}

function readDistanceException(v) {
  if (v === 0) return "blind spot alarm release";
  if (v === 1) return "blind spot alarm";
  if (v === 2) return "no target";
  if (v === 3) return "sensor exception";
  return "exception " + v;
}