core bluetooth crash in iOS 7

Question

I have developed a bluetooth app, which runs fine on iOS 6, but when I run it on iOS 7 the application crashes in the -didDiscoverPeripheral call back. The crash info suggests that a release is called on the CBPeripheral object. I have used ARC for memory management, here is my declaration,initialisation of the CBPeripheral object and the call back code:

@interface BrLEDiscovery () <CBCentralManagerDelegate, CBPeripheralDelegate> {
    CBCentralManager    *centralManager;
    CBPeripheral *currentperipheral;
    BOOL                pendingInit;
}


- (id) init
{
    self = [super init];
    if (self) {
        pendingInit = YES;
        centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()];
       currentperipheral=[[CBPeripheral alloc]init];
        founddevice=FALSE;
        foundPeripherals = [[NSMutableArray alloc] init];
        connectedServices = [[NSMutableArray alloc] init];

    }
    return self;
}

- (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI
{ NSLog(@"Found Peripheral %@",[peripheral name]);

    if ([[peripheral name] isEqualToString:peripheralname]) {
        founddevice=TRUE;
        currentperipheral=peripheral;

        if (![foundPeripherals containsObject:peripheral]) {
            [foundPeripherals addObject:peripheral];
            [discoveryDelegate discoveryDidRefresh];
            [discoveryDelegate DiscoveryDidFindDevice:peripheral];

        }

        [RecursiveScanTimer invalidate];
    }


}

Answer 1

From your description, it's pretty likely to be crashing on this line:

currentperipheral=peripheral;

To me, it's kinda messy allocating a CBPeripheral object in your init and then assigning the peripheral at an unknown time later (especially with arc). If you want to keep reference to a discovered peripheral, just create a CBPeripheral object in your interface, retain the discovered peripheral, and assign it to your interface peripheral.

Just try something like this:

currentPeripheral = [discoveredPeripheral retain];//where discoveredPeripheral is the one given in the delegate callback

I personally don't use arc for any of my corebluetooth related applications..You need to be really careful with the corebluetooth framework and peripheral references though...it gets messyyy.

Note: If you do not always need to have direct contact with the peripheral, it's often handy to just keep a record of the CFUUIDRef (or identifier for iOS 7) and just retrieve the peripheral whenever you need it... Good luck!