Milesight UC511: LoRaWAN Solenoid Valve Controller

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): version, SN, class. Length is field-specific.
    if (channel === 0xff) { i += deviceInfoLen(type, bytes, i); continue; }

    // Battery (%)
    if (channel === 0x01 && type === 0x75) { data.battery = bytes[i]; i += 1; continue; }

    // Valve 1 / valve 2 status: 1 byte (0 closed, 1 open; 0xFF = delayed-command ack)
    if (channel === 0x03 && type === 0x01) { data.valve_1 = readValve(bytes[i]); i += 1; continue; }
    if (channel === 0x05 && type === 0x01) { data.valve_2 = readValve(bytes[i]); i += 1; continue; }

    // Valve 1 / valve 2 flow pulses: UINT32 little-endian (4 bytes)
    if (channel === 0x04 && type === 0xc8) { data.valve_1_pulse = readUInt32LE(bytes, i); i += 4; continue; }
    if (channel === 0x06 && type === 0xc8) { data.valve_2_pulse = readUInt32LE(bytes, i); i += 4; continue; }

    // GPIO 1 / GPIO 2 status: 1 byte (hardware/firmware dependent)
    if (channel === 0x07 && type === 0x01) { data.gpio_1 = bytes[i]; i += 1; continue; }
    if (channel === 0x08 && type === 0x01) { data.gpio_2 = bytes[i]; i += 1; continue; }

    // Pipe pressure (kPa): UINT16 little-endian, on pressure variants
    if (channel === 0x09 && type === 0x7b) { data.pressure = readUInt16LE(bytes, i); i += 2; continue; }

    // Unknown channel: stop. Downlink-response, history and task-status
    // segments are deployment-specific and decoded per rollout.
    break;
  }
  return { data: data };
}

function readValve(v) {
  if (v === 0xff) return "command_ack";
  return v === 1 ? "open" : "closed";
}
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, b, i) {
  void b; void i;
  if (type === 0x01 || type === 0x0f || type === 0x0b || type === 0xfe) return 1; // version, class, status, reset
  if (type === 0x09 || type === 0x0a || type === 0xff) return 2;                  // hw / fw / TSL version
  if (type === 0x16) return 8;                                                    // serial number
  return 1;
}