CODEWITHSUNDEEP
ioscore-bluetooth
Mc Sibi
Mc Sibi

Reputation: 119

CoreBluetooth[WARNING] Unknown error: 311 Occurs when repeatedly connect and disconnect using CoreBluetooth Framework in iOS

When I try to connect Bluetooth devices, it repeatedly fails to connect and shows the error CoreBluetooth[WARNING] Unknown error: 311. I am using 2 iPod 5 Touch devices.

Upvotes: 2

Views: 1837

Answers (2)

cocteau
cocteau

Reputation: 31

If you are getting the error after connecting for a while it seems likely this analysis and solution will be of help:

http://lists.apple.com/archives/bluetooth-dev/2013/Jan/msg00069.html

Upvotes: -1

numist
numist

Reputation: 627

I've been running into this too and it appears to be a bug in Core Bluetooth's XPC communication:

2013-03-22 14:49:24.652 Buggy[985:907] Connecting to peripheral <CBConcretePeripheral: 0x1dd4e150 UUID = (null), Name = "iPhone 5 #003014", IsConnected = NO>
2013-03-22 14:49:24.659 Buggy[985:907] CoreBluetooth[WARNING] Unknown error: 311
2013-03-22 14:49:24.661 Buggy[985:907] Failed to connect to peripheral <CBConcretePeripheral: 0x1dd4e150 UUID = (null), Name = "iPhone 5 #003014", IsConnected = NO>
2013-03-22 14:49:24.689 Buggy[985:907] Discovered peripheral <CBConcretePeripheral: 0x1dd644d0 UUID = (null), Name = "iPhone 5 #003014", IsConnected = NO> with advertisement data {
    kCBAdvDataLocalName = "iPhone 5 #003014";
    kCBAdvDataServiceUUIDs =     (
        "Unknown (<b2e74c08 96094371 a8f0978c 655700ea>)"
    );
}, RSSI: -50
2013-03-22 14:49:24.692 Buggy[985:907] Connecting to peripheral <CBConcretePeripheral: 0x1dd644d0 UUID = (null), Name = "iPhone 5 #003014", IsConnected = NO>
2013-03-22 14:49:45.035 Buggy[985:110b] CoreBluetooth[ERROR] XPC connection interrupted, resetting
2013-03-22 14:49:45.050 Buggy[985:907] Central manager updated state to: 1
2013-03-22 14:49:45.116 Buggy[985:907] Central manager updated state to: 4
2013-03-22 14:49:47.271 Buggy[985:907] Central manager updated state to: 5

After this point things started working again, at least until the error 311 loop struck again a few minutes later.

Here's a workaround that's been reliable for me:

// In centralManager:didFailToConnectPeripheral:error:, ARC enabled
if (error.code == 0) {
    self.centralManager.delegate = nil;
    self.centralManager = nil;
    // Remove all references to any peripherals you've been interacting with
    [self.peripherals removeAllObjects];

    /* Some delay (more than the next iteration of the runloop, less than 2 seconds) is required in order to:
     * • Allow ARC to drain the autorelease pool, ensuring destruction of the centralManager
     * • Allow Core Bluetooth to turn off the radio.
     *
     * This means that this workaround might not work if:
     * • Your code has another active central manager somewhere
     * • Another app is using BLE (in theory; I haven't tested this)
     */
    double delayInSeconds = 2.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        self.centralManager = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()];
        [self startScanning];
    });
}

Upvotes: 7

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