How to wake up iOS app with bluetooth signal (BLE)

Question

When using the BLE with CoreBluetooth (no iBeacon), is there a way to wake an app that is not running when the device receives a Bluetooth signal?

I'm simulating a beacon with the RedBearlab's BLE Shield (http://redbearlab.com/bleshield/).

Thanks, DAN

* UPDATE 03/05/14 *

It looks like Apple has introduced a major update with iOS 7.1: now iOS will open your app for you if it detects a UUID that matches your app. The app only needs to be installed, it doesn't have to be running (logic in AppDelegate needed to answer the wake-up call).

Answer 1

If the app was running in the background and then closed (I mean here terminated - and you do not see it anymore in the list of background apps when you double click the home button) due to memory pressure from other apps, then the iOS will take care of waking it up again when a delegate is called (assuming you have background modes listed in .plist).

If the app was running in the background and then closed by the user (again I mean here terminated. So the user double clicked to get the list of apps running in the background and then clicked on your app in the background list until it wiggled and then pressed the 'x' next to the app to kill it) then this is a clear indication that the user does not want the app running in the background and the app will not be re-launched. The user has to relaunch the app for its delegates to start functioning again in the background (new in iOS7).

Update: I am not sure if this is in the documentation but it is in CoreBluetooth WWDC 2013 Video. I recommend you watch it. They spent a good portion of the video on how CoreBluetooth behaves in the background.

Answer 2

From what I understand, if your app has not previously connected with the BLE Peripheral, then no.

If your app has previously connected with the BLE Peripheral, then use:

-connectPeripheral:options

Connection requests don't time out. The best place to call this method is when your app loses connectivity with the BLE peripheral. You will get notified when you lose connection to the peripheral in the CBCentralManagerDelegate Protocol:

-centralManager: didDisconnectPeripheral: error

So the next time your App comes in range of the BLE Peripheral, it will trigger this method. Also note that you will need to set up State Preservation and Restoration when you initialize a CBCentralManager.

Answer 3

https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/CoreBluetoothBackgroundProcessingForIOSApps/PerformingTasksWhileYourAppIsInTheBackground.html

the system wakes up your app when any of the CBCentralManagerDelegate or CBPeripheralDelegate delegate methods are invoked, allowing your app to handle important central role events, such as when a connection is established or torn down, when a peripheral sends updated characteristic values, and when a central manager’s state changes.

To perform certain peripheral role tasks while in the background, you must include the UIBackgroundModes key with the bluetooth-peripheral value in your app’s Info.plist file. When this key-value pair is included in the app’s Info.plist file, the system wakes up your app to process read, write, and subscription events.

Answer 4

You could try to declare voip in info.plist. For the time being, my application was automatically relaunched after a time, even user terminated it.