app.js

const dgram = require('dgram');
const serverSocket = dgram.createSocket('udp4');
const multicastAddress = '224.0.0.50';
const multicastPort = 4321;
const serverPort = 9898;

var AqaraAccessoryFactory;


function startServer() {
  // Show some message
  serverSocket.on('listening', () => {
    serverSocket.setMulticastTTL(128);
    serverSocket.addMembership(multicastAddress);
  });

  serverSocket.on('message', function(msg, rinfo) {
    console.log(msg.toString(), rinfo);
  });

  // Start server
  serverSocket.bind(serverPort);
}

function search() {
  var whoisCommand = '{"cmd": "whois"}';
  serverSocket.send(whoisCommand, 0, whoisCommand.length, multicastPort, multicastAddress);
  // console.log("send %s to %s:%d", whoisCommand, multicastAddress, multicastPort);
}

startServer();
setInterval(search, 1000);