title: events.js:72 throw er; // Unhandled 'error' event
body: <p>I am trying to use node-ar-drone package for controlling and interfacing with an AR Parrot Drone 2 but I get the following errors after connecting to the wireless network of the drone in my OSX Yosemite:</p>
  
  <pre><code>587214779:examples mona$ node png-stream.js 
  Connecting png stream ...
  
  events.js:72
          throw er; // Unhandled 'error' event
                ^
  Error: listen EADDRINUSE
      at errnoException (net.js:901:11)
      at Server._listen2 (net.js:1039:14)
      at listen (net.js:1061:10)
      at Server.listen (net.js:1127:5)
      at Object.&lt;anonymous&gt; (/Users/mona/iotlab/armyo/node-ar-drone/examples/png-stream.js:28:8)
      at Module._compile (module.js:456:26)
      at Object.Module._extensions..js (module.js:474:10)
      at Module.load (module.js:356:32)
      at Function.Module._load (module.js:312:12)
      at Function.Module.runMain (module.js:497:10)
  587214779:examples mona$ 
  </code></pre>
  
  <p>I wonder what the error might be?</p>
  
  <p>For more information, I have followed these tutorials:</p>
  
  <pre><code>git clone https://github.com/felixge/node-ar-drone.git
  </code></pre>
  
  <p>install it using this command:</p>
  
  <pre><code>npm install git://github.com/felixge/node-ar-drone.git
  </code></pre>
  
  <p>P.S.: I am literally running an example in the example directory and I am not changing any code.</p>