text: var express = require('express');
  var app = express();
  var http = require('http').createServer(app);
  var io = require('socket.io')(http);
  var robot = require('robotjs');
  var ip = require('ip');
  
  app.use('/', express.static(__dirname + '/public/'));
  
  app.get('/', function (req, res) {
    res.sendFile(__dirname + '/public/controller.html');
  });
  
  io.on('connection', function (socket) {
    console.log('a user connected');
  
    socket.on('touchstart', key => {
      console.log('touchstart', key);
      robot.keyToggle(key, 'down');
    });
    socket.on('touchend', key => {
      console.log('touchend', key);
      robot.keyToggle(key, 'up');
    });
  });
  
  http.listen(3000, function () {
    console.log('listening on *:3000');
    console.log('connect devices to ' + ip.address());
  });
  