server.js

var express = require('express')
  , ejs = require('ejs')
  , arDrone = require("ar-drone")
  , control = arDrone.createUdpControl()
  // , pngStream = arDrone.createClient().getPngStream()
  , TcpVideoStream = arDrone.Client.TcpVideoStream
  , PngEncoder = arDrone.Client.PngEncoder
  , start = Date.now()
  , Drone
  , drone
  , ref = {}
  , pcmd = {}
  , app = express()
  , port
  , io
  , __bind
  ;

__bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };


app.configure(function() {
  app.use(express.bodyParser());
  app.set('dirname', __dirname);
  app.use(app.router);
  app.use(express["static"](__dirname + "/public/"));
  app.use(express.errorHandler({
    dumpExceptions: true,
    showStack: true
  }));
  return app.set('views', __dirname + "/views/");
});

app.get("/", function(req, res) {
  return res.render('index.ejs');
});

port = process.env.PORT || 8080;
app.listen(port);
console.log("Listening on Port '" + port + "'");

Drone = (function() {

  var videoStream
    , pngEncoder
    , callback
    ;

  function Drone(speed) {
    this.decreaseSpeed = __bind(this.decreaseSpeed, this);
    this.increaseSpeed = __bind(this.increaseSpeed, this);
    this.commands = __bind(this.commands, this);
    this.speed = speed;
    this.accel = 0.01;
    this.takingPhotos = false;
  }

  Drone.prototype.takeoff = function() {
    console.log("Takeoff ...");
    ref.emergency = false;
    return ref.fly = true;

    if (!this.takingPhotos) {
      this.takingPhotos = true;
      setTimeout(function() {
        drone.takePhoto()
      }, 1 *1000);
    }

  };

  Drone.prototype.land = function() {
    console.log("Landing ...");
    ref.fly = false;
    return pcmd = {};
  };

  Drone.prototype.stop = function() {
    return pcmd = {};
  };

  Drone.prototype.commands = function(names) {
    var name, _i, _len;
    pcmd = {};
    for (_i = 0, _len = names.length; _i < _len; _i++) {
      name = names[_i];
      pcmd[name] = this.speed;
    }
    return console.log('PCMD: ', pcmd);
  };

  Drone.prototype.increaseSpeed = function() {
    this.speed += this.accel;
    return console.log(this.speed);
  };

  Drone.prototype.decreaseSpeed = function() {
    this.speed -= this.accel;
    return console.log(this.speed);
  };

  Drone.prototype.disableEmergency = function() {
    this.disablEemergency = false;
  };

  Drone.prototype.takePhoto = function() {

    if (!videoStream && !pngEncoder) {
      console.log("initializing video stream and png encoder")
      videoStream = videoStream || new TcpVideoStream({});
      pngEncoder = pngEncoder || new PngEncoder({});

      callback = function(err) {
        if (err !== null) {
          console.log('TcpVideoStream error: %s', err.message);
          console.log(err);
          setTimeout(function () {
              console.log('Attempting to reconnect to TcpVideoStream...');
              videoStream.connect(callback);
          }, 3 *1000);
        }
      };

      videoStream.connect(callback);

      videoStream.on('error', callback);
      videoStream.on('data', function(data) {
        console.log("data received from video stream - fwd to png Encoder")
        pngEncoder.write(data);
      });
    }
  };

  return Drone;
})();

setInterval((function() {
  control.ref(ref);
  control.pcmd(pcmd);
  return control.flush();
}), 30);

drone = new Drone(0.5);
drone.speed = 0.2;
drone.disableEmergency();
console.log(drone);

// setTimeout(function() {
//   drone.takePhoto()
// }, 3 *1000);
// setTimeout(function() {
//   setInterval(drone.takePhoto, 1.5 *1000);
// }, 3 *1000);


io = require("socket.io").listen(8081);

io.sockets.on("connection", function(socket) {
  socket.on("takeoff", drone.takeoff);
  socket.on("land", drone.land);
  socket.on("stop", drone.stop);
  socket.on("command", drone.commands);
  socket.on("increaseSpeed", drone.increaseSpeed);
  socket.on("disableEmergency", drone.disableEmergency);
  // socket.on("takePhoto", drone.takePhoto);
  // socket.on("takePhoto", function() { console.log("take photo") });
  return socket.on("decreaseSpeed", drone.decreaseSpeed);
});

views_index.ejs

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">

  <title>Controls</title>
  <style type="text/css" media="screen">
    #controls{
      position:absolute;
      top:0;
      right:0;
      padding:10px;
    }
  </style>
</head>
<body class="deck-container">

<div id='log'>

</div>

<div id='controls'>

</div>

<script src="jquery-1.7.2.min.js"></script>
<script src="keyboard.js"></script>

<script src="http://localhost:8081/socket.io/socket.io.js"></script>
<script>
  var socket = io.connect('http://localhost:8081');
  socket.on('news', function (data) {
    console.log(data);
    socket.emit('my other event', { my: '2' });
  });

  var timer
  var log
  var mapping = {
    'space': 'takeoff',
    'x' : 'land',
    'w' : 'front',
    's' : 'back',
    'a' : 'left',
    'd' : 'right',
    'j' : 'counterClockwise',
    'l' : 'clockwise',
    'i' : 'up',
    'k' : 'down',
    'u' : 'disableEmergency',
    // 't' : 'takePhoto',
    'dash': 'decreaseSpeed',
    'equal': 'increaseSpeed',
  }

  $(function(){
    timer = setInterval(tick, 30);

    log = $('#log')

    for (var k in mapping) {
      if (mapping.hasOwnProperty(k)) {
        $('#controls').append(k + ' => ' + mapping[k] + '<br/>');
      }
    }
  });

  var takePhoto = function() {
    socket.emit('takePhoto');
  };

  var tick = function(){
    keys = KeyboardJS.activeKeys()
    log.text(keys)

    if(keys.length > 0) {

      commands = []
      for (var i = 0; i < keys.length; i++) {
        key = keys[i]
        command = mapping[key]
        if(command != undefined){
          commands.push(command)
        }
      }

      if(commands.length > 0){
        log.text(commands)
        if(commands[0] === 'takeoff'){
          socket.emit('takeoff');
        } else if(commands[0] === 'land'){
          socket.emit('land');
        } else if(commands[0] === 'increaseSpeed'){
          socket.emit('increaseSpeed');
        } else if(commands[0] === 'decreaseSpeed'){
          socket.emit('decreaseSpeed');
        } else if(commands[0] === 'takePhoto'){
          socket.emit('takePhoto');
        } else {
          socket.emit('command', commands);
        }
      } else{
        socket.emit('stop');
        log.text('')
      }
    } else{
      log.text('')
      socket.emit('stop');
    }
  }

</script>
</body>
</html>