index.old.js

import dotenv from 'dotenv';
import mqtt from 'mqtt';
import * as nobleModule from '@abandonware/noble';
import * as MiParser from './parsers/mi_parser.js';
import * as QPParser from './parsers/qingping_parser.js';
import _ from 'lodash';

const noble = nobleModule.default;

const parsers = [MiParser, QPParser];

dotenv.config();

const topic = process.env.MQTT_TOPIC || 'ble_sensors';
const machineName = process.env.MACHINE_NAME || 'needsNameInConfig';

const mqttClient = mqtt.connect(`mqtt://${process.env.MQTT_HOSTNAME}`, {
  username: process.env.MQTT_USERNAME,
  password: process.env.MQTT_PASSWORD
});

function decodeData(peripheral) {
  if (!peripheral.advertisement.serviceData) return;
  //console.log(peripheral.advertisement.serviceUuids)
  const { advertisement: { serviceData } = {}, id, address } = peripheral || {};

  serviceData.forEach((iter) => {
    if (!iter) return;
    try {
      let result = parsers.reduce((a, rootParser) => {
        if (_.includes(rootParser.SERVICE_DATA_UUIDS, iter.uuid.toLowerCase())) {
          return new rootParser.Parser(iter.data).parse();
        }
        return a;
      }, null);

      if (!result) return;

      let wrappedResult = {
        macAddress: result.macAddress,
        rssi: peripheral.rssi,
        receivedFrom: machineName,
        parser: result.parser,
        result: result.info
      };

      console.info('PUB:', wrappedResult.macAddress, result.info);
      mqttClient.publish(topic, JSON.stringify(wrappedResult));
    } catch (error) {
      console.error(error);
    }
  });
}

function onDiscovery(peripheral) {
  // peripheral.rssi                             - signal strength
  // peripheral.address                          - MAC address
  // peripheral.advertisement.localName          - device's name
  // peripheral.advertisement.manufacturerData   - manufacturer-specific data
  // peripheral.advertisement.serviceData        - normal advertisement service data
  // ignore devices with no manufacturer data
  if (!peripheral.advertisement.serviceData) return;
  // output what we have

  decodeData(peripheral);

  if (process.env.BLE_DEBUG == 'true') {
    console.debug(
      peripheral.address || 'no-address-yet',
      JSON.stringify(peripheral.advertisement.localName || peripheral.address || 'no-name'),
      peripheral.rssi,
      signalStrengthPercentage(peripheral.rssi)
    );
  }
}

noble.on('warning', (warning) => console.warn(warning));
noble.on('discover', onDiscovery);

noble.on('stateChange', function (state) {
  if (state != 'poweredOn') return;
  console.log('🚀 Starting BLE scan...');
  noble.startScanning([], true);
});

// bluetooth lib start / stop events
noble.on('scanStart', function () {
  console.log('BLE Scanning started.');
});
noble.on('scanStop', function () {
  console.log('BLE Scanning stopped.');
  mqttClient.end();
});

function signalStrengthBars(rssi) {
  let bars = '▂▄▆█';
  if (rssi >= -65) {
    // strong
    return bars;
  }

  if (rssi >= -73) {
    // good
    return bars.substr(0, 3);
  }

  if (rssi >= -80) {
    return bars.substr(0, 2);
  }

  if (rssi >= -94) {
    return bars.substr(0, 1);
  }

  return '─';
}

function signalStrengthPercentage(rssi) {
  // Quality as percentage max -40 min -110
  return (((rssi + 110) * 10) / 7).toFixed(0) + '%';
}