What causes CBCentralManagerStateUnknown in iOS?

Question

Why do I get CBCentralManagerStateUnknown on an iPad 2 when using this simple code?

- (BOOL)viewDidLoad {

    bluetoothManager = [[CBCentralManager         


        

Answer 1

CBCentralManagerStateUnknown simply means iOS has started the BLE process, but has not completed initialization. Give it a moment, and the state will change.

In general, you will "give it a moment" by detecting a state chang in a CBCentralManagerDelegate delegate handler rather than looking at it right after the initialization call. You will implement

- (void) centralManagerDidUpdateState: (CBCentralManager *) central;

There are some good examples that show this, such as Apple's heart rate monitor.