index.mjs

import { IoTDataPlaneClient, PublishCommand } from "@aws-sdk/client-iot-data-plane";

// Please fill in your `endpoint` in the `region` below. For example: 'us-east-1'
const client = new IoTDataPlaneClient({ region: 'us-east-1' });

export const handler = async (event) => {
  var data = Buffer.from(event.PayloadData, 'base64');
  var chars = [...data];
  var params = Decoder(chars, event.WirelessMetadata.LoRaWAN.FPort);
  params["EUI"]= event.WirelessMetadata.LoRaWAN.DevEui;

  // Please fill in the MQTT message topic you will use when sending to the MQTT server in the "topic" section below.
  const command = new PublishCommand({
    topic: "sdk/test/python",
    payload: JSON.stringify(params),
    qos: 0
  });

  return new Promise((resolve, reject) => {
    client.send(command)
    .then((data) => {
      // console.log('=== Publish ===');
      // console.log("publish data: ", data);

      const returnData = {
        statusCode: 200,
        body: params,
      };
      resolve(returnData);
    })
    .catch((err) => {
      // console.log('=== Error ===');
      // console.log("ERROR => " + JSON.stringify(err));
      
      const returnData = {
        statusCode: 400,
        body: err,
      };
      reject(returnData);
    });
  });
};

function Decoder(bytes, fport) {
  var response = {};
  lppDecode(bytes, 1).forEach(function (field) {
    response[field['name'] + '_' + field['channel']] = field['value'];
  });

  return response;
}

function lppDecode(bytes) {
  var sensor_types = {
    0: { 'size': 1, 'name': 'digital_in', 'signed': false, 'divisor': 1 },
    1: { 'size': 1, 'name': 'digital_out', 'signed': false, 'divisor': 1 },
    2: { 'size': 2, 'name': 'analog_in', 'signed': true, 'divisor': 100 },
    3: { 'size': 2, 'name': 'analog_out', 'signed': true, 'divisor': 100 },
    100: { 'size': 4, 'name': 'generic', 'signed': false, 'divisor': 1 },
    101: { 'size': 2, 'name': 'illuminance', 'signed': false, 'divisor': 1 },  //unit:Lux
    102: { 'size': 1, 'name': 'presence', 'signed': false, 'divisor': 1 },
    103: { 'size': 2, 'name': 'temperature', 'signed': true, 'divisor': 10 },  //unit:℃
    104: { 'size': 1, 'name': 'humidity', 'signed': false, 'divisor': 2 },
    112: { 'size': 2, 'name': 'humidity_prec', 'signed': true, 'divisor': 10 },  //unit:%RH
    113: { 'size': 6, 'name': 'accelerometer', 'signed': true, 'divisor': 1000 },
    115: { 'size': 2, 'name': 'barometer', 'signed': false, 'divisor': 10 },  //unit:hPa
    116: { 'size': 2, 'name': 'voltage', 'signed': false, 'divisor': 100 },
    117: { 'size': 2, 'name': 'current', 'signed': false, 'divisor': 1000 },
    118: { 'size': 4, 'name': 'frequency', 'signed': false, 'divisor': 1 },
    120: { 'size': 1, 'name': 'percentage', 'signed': false, 'divisor': 1 },
    121: { 'size': 2, 'name': 'altitude', 'signed': true, 'divisor': 1 },
    125: { 'size': 2, 'name': 'concentration', 'signed': false, 'divisor': 1 },
    128: { 'size': 2, 'name': 'power', 'signed': false, 'divisor': 1 },
    130: { 'size': 4, 'name': 'distance', 'signed': false, 'divisor': 1000 },
    131: { 'size': 4, 'name': 'energy', 'signed': false, 'divisor': 1000 },
    132: { 'size': 2, 'name': 'direction', 'signed': false, 'divisor': 1 },
    133: { 'size': 4, 'name': 'time', 'signed': false, 'divisor': 1 },
    134: { 'size': 6, 'name': 'gyrometer', 'signed': true, 'divisor': 100 },
    135: { 'size': 3, 'name': 'colour', 'signed': false, 'divisor': 1 },
    136: { 'size': 9, 'name': 'gps', 'signed': true, 'divisor': [10000, 10000, 100] },
    137: { 'size': 11, 'name': 'gps', 'signed': true, 'divisor': [1000000, 1000000, 100] },
    138: { 'size': 2, 'name': 'voc', 'signed': false, 'divisor': 1 },
    142: { 'size': 1, 'name': 'switch', 'signed': false, 'divisor': 1 },
    188: { 'size': 2, 'name': 'soil_moist', 'signed': false, 'divisor': 10 },
    190: { 'size': 2, 'name': 'wind_speed', 'signed': false, 'divisor': 100 },  //unit:m/s
    191: { 'size': 2, 'name': 'wind_direction', 'signed': false, 'divisor': 1 },  //unit:°
    192: { 'size': 2, 'name': 'soil_ec', 'signed': false, 'divisor': 1000 },
    193: { 'size': 2, 'name': 'soil_ph_h', 'signed': false, 'divisor': 100 },
    194: { 'size': 2, 'name': 'soil_ph_l', 'signed': false, 'divisor': 10 },
    195: { 'size': 2, 'name': 'pyranometer', 'signed': false, 'divisor': 1 },
    203: { 'size': 1, 'name': 'light', 'signed': false, 'divisor': 1 },

    //Tongdy 20230805 		
    211: { 'size': 2, 'name': 'co2', 'signed': true, 'divisor': 1 },  //unit:ppm
    212: { 'size': 2, 'name': 'tvoc', 'signed': true, 'divisor': 1000 },  //unit:mg/m3
    213: { 'size': 2, 'name': 'pm0.3', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    214: { 'size': 2, 'name': 'pm0.5', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    215: { 'size': 2, 'name': 'pm1', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    216: { 'size': 2, 'name': 'pm2.5', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    217: { 'size': 2, 'name': 'pm4', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    218: { 'size': 2, 'name': 'pm10', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    219: { 'size': 2, 'name': 'pm100', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    220: { 'size': 2, 'name': 'co', 'signed': true, 'divisor': 10 },  //unit:mg/m3
    221: { 'size': 2, 'name': 'o3', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    222: { 'size': 2, 'name': 'so2', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    223: { 'size': 2, 'name': 'no2', 'signed': true, 'divisor': 1 },  //unit:ug/m3
    224: { 'size': 2, 'name': 'hcho', 'signed': true, 'divisor': 1000 },  //unit:mg/m3			
    225: { 'size': 2, 'name': 'noise', 'signed': true, 'divisor': 10 },  //unit:dB(A)
  };

  function arrayToDecimal(stream, is_signed, divisor) {

    var value = 0;
    for (var i = 0; i < stream.length; i++) {
      if (stream[i] > 0xFF)
        throw 'Byte value overflow!';
      value = (value << 8) | stream[i];
    }

    if (is_signed) {
      var edge = 1 << (stream.length) * 8;  // 0x1000..
      var max = (edge - 1) >> 1;             // 0x0FFF.. >> 1
      value = (value > max) ? value - edge : value;
    }

    value /= divisor;

    return value;

  }

  var sensors = [];
  var i = 0;
  while (i < bytes.length) {

    var s_no = bytes[i++];
    var s_type = bytes[i++];
    if (typeof sensor_types[s_type] == 'undefined') {
      throw 'Sensor type error!: ' + s_type;
    }

    var s_value = 0;
    var type = sensor_types[s_type];
    switch (s_type) {

      case 113:   // Accelerometer
      case 134:   // Gyrometer
        s_value = {
          'x': arrayToDecimal(bytes.slice(i + 0, i + 2), type.signed, type.divisor),
          'y': arrayToDecimal(bytes.slice(i + 2, i + 4), type.signed, type.divisor),
          'z': arrayToDecimal(bytes.slice(i + 4, i + 6), type.signed, type.divisor)
        };
        break;
      case 136:   // GPS Location
        s_value = {
          'latitude': arrayToDecimal(bytes.slice(i + 0, i + 3), type.signed, type.divisor[0]),
          'longitude': arrayToDecimal(bytes.slice(i + 3, i + 6), type.signed, type.divisor[1]),
          'altitude': arrayToDecimal(bytes.slice(i + 6, i + 9), type.signed, type.divisor[2])
        };
        break;
      case 137:   // Precise GPS Location
        s_value = {
          'latitude': arrayToDecimal(bytes.slice(i + 0, i + 4), type.signed, type.divisor[0]),
          'longitude': arrayToDecimal(bytes.slice(i + 4, i + 8), type.signed, type.divisor[1]),
          'altitude': arrayToDecimal(bytes.slice(i + 8, i + 11), type.signed, type.divisor[2])
        };
        sensors.push({
          'channel': s_no,
          'type': s_type,
          'name': 'location',
          'value': "(" + s_value.latitude + "," + s_value.longitude + ")"
        });
        sensors.push({
          'channel': s_no,
          'type': s_type,
          'name': 'altitude',
          'value': s_value.altitude
        });
        break;
      case 135:   // Colour
        s_value = {
          'r': arrayToDecimal(bytes.slice(i + 0, i + 1), type.signed, type.divisor),
          'g': arrayToDecimal(bytes.slice(i + 1, i + 2), type.signed, type.divisor),
          'b': arrayToDecimal(bytes.slice(i + 2, i + 3), type.signed, type.divisor)
        };
        break;

      default:    // All the rest
        s_value = arrayToDecimal(bytes.slice(i, i + type.size), type.signed, type.divisor);
        break;
    }

    sensors.push({
      'channel': s_no,
      'type': s_type,
      'name': type.name,
      'value': s_value
    });

    i += type.size;

  }

  return sensors;
}