sender.js

module.exports = function (host, payload, callback) {
  var PORT = 80;

  var broadcast = new Buffer('5aa5aa555aa5aa55000000000000000000000000000000000000000000000000a2f3000037276a00528022a2f00d43b40100000090c80000178a382be0b953f51e066fa79407190dfec18c688af01de0dc428a1f11ace75a10dacb9050c542110e29cc734468d0ae6c476c87c99544bbd0587d14182256eb3b23c674c57d8a2852412c1c335003d6a5fa1d3080c9d1b6210983b3879657a6', 'hex');

  var message = new Buffer(payload, 'hex');

  var dgram = require('dgram');
  var client = dgram.createSocket('udp4');

  client.send(broadcast, 0, broadcast.length, PORT, host, function(err, bytes) {
    if (err) throw err;
    console.log('UDP message sent to ' + host +':'+ PORT);

    client.send(message, 0, message.length, PORT, host, function(err, bytes) {
      if (err) throw err;
      console.log('UDP message sent to ' + host +':'+ PORT);
      client.close();

      callback(err);
    });

  });
}