Disconnecting and Reconnecting to OBD2 adapter / Crash

[ron3001]

I've been using this library to establish BLE communication between iOS device and a vehicle for a while now - it helps a lot. Now I am getting a crash from the library, trying to disconnect the LTBTLESerialTransporter object. The crash is in:

-(void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
{
    LOG( @"Did disconnect %@: %@", peripheral, error );
    if ( peripheral == _adapter )
    {
        [_inputStream close];
        [_outputStream close];
    }
}

If there is established communication and the disconnect method is just called on the LTBTLESerialTransporter object (which is after that set to nil) there is no issue. But if the OBD2 adapter is disconnected from the vehicle and therefore the OBD2AdapterStateGone notification is received - on calling disconnect + setting the LTBTLESerialTransporter object to nil or just setting it to nil - the crash happens. The error is EXC_BAD_ACCESS KERN_INVALID_ADDRESS and happens on -[LTBTLEWriteCharacteristicStream close] . Is there more correct way to disconnect at this point - to avoid the crash and be able to reconnect after that? How is it intended to work?

[mickeyl]

Thanks for your report. The EXC_BAD_ACCESS was due to the delegate being invalid, setting this to weak should fix it. To show how I would handle a forceful disconnect/reconnect, I tweaked the example.

Could you check whether this works for you?

[ron3001]

Thanks a lot for the demo tweak and change in the library! Tested with the example and there were no crashes there. My implementation also did not crash with the latest changes, but I will need to test more. I have one question. Since the crash was on [LTBTLEWriteCharacteristicStream close] shouldn't also the delegate there be changed to weak?

[mickeyl]

Absolutely, thanks. Closing this now – please reopen, if necessary.