title: iOS CoreBluetooth passively check if Bluetooth is enabled without prompting user to turn Bluetooth on
body: <p>The scenario is as follows.  I have an already deployed app being used by people.  I am <em>considering</em> implementing some experimental Bluetooth Low Energy features, but before I do, I want to conduct an "in the wild" survey of the number of users who already have Bluetooth turned on/leave Bluetooth on all the time.  So, I would just like to check this in the background and send back to a server statistics on number of users with Bluetooth already on, without ever actually using Bluetooth communications.</p>
  
  <p>I have successfully instantiated a <code>CBCentralManager</code> in my app and can retrieve the Bluetooth status both immediately after instantiation and when the Bluetooth state updates via <a href="http://developer.apple.com/library/mac/#documentation/CoreBluetooth/Reference/CBCentralManagerDelegate_Protocol/translated_content/CBCentralManagerDelegate.html#//apple_ref/occ/intfm/CBCentralManagerDelegate/centralManagerDidUpdateState%3a"><code>centralManagerDidUpdateState:</code></a>.  So that is all good.  The problem I am having is that if the state is <code>CBCentralManagerStatePoweredOff</code>, then the device brings up an alert prompting the user to "Turn On Bluetooth to Allow [app name] to Connect to Accessories".  It is this prompt I am trying to avoid.  At this stage I just wish to survey the number of users who leave Bluetooth On - I don't wish to use the Bluetooth connection.  </p>
  
  <p>So, <em>is there a way to check the Bluetooth status without prompting the user if you don't intend on using the Bluetooth connection?</em></p>