title: Notification Center - Obervers not working properly
body: <p>I'm developing an app which has to communicate with an external accessory. The app has several requests to send to the external accessory. </p>
  
  <p>My problem:</p>
  
  <p>I'm using observers in different places (classes), I'm adding the following observers in <code>viewDidLoad</code>:</p>
  
  <pre><code>    [[NSNotificationCenter defaultCenter] addObserver:self
  selector:@selector(observer1:)
      name:EADSessionDataReceivedNotification object:nil];
  
      [[NSNotificationCenter defaultCenter] addObserver:self
  selector:@selector(observer2:)
      name:EADSessionDataReceivedNotification object:nil];
  
      [[NSNotificationCenter defaultCenter] addObserver:self
  selector:@selector(observer3:)
      name:EADSessionDataReceivedNotification object:nil];
  </code></pre>
  
  <p>The 1st Observer works very well, but I'm getting problems with the other two. They don't respond until the first one has been used. Do I need to add something else?</p>
  
  <p>The flow is as follows:</p>
  
  <ol>
  <li><p>Send a request to ext-acc and fire a flag to know which observer will take the returned data</p></li>
  <li><p>ext-acc responds with data</p></li>
  <li><p>The receiver method pushes a notification into notification center.</p></li>
  <li><p>The observer with the flag in 1 will take the data (at this point do I need to remove the notification since no one else will need it?). </p></li>
  </ol>