#define TRANSFER_CHARACTERISTIC_UUID    @"08590F7E-DB05-467E-8757-72F6FAEB13D4"

- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{
    // Again, we loop through the array, just in case.
    for (CBCharacteristic *characteristic in service.characteristics) {

        // And check if it's the right one
        if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:TRANSFER_CHARACTERISTIC_UUID]]) {

            // If it is, subscribe to it
            [peripheral setNotifyValue:YES forCharacteristic:characteristic];
        }
    }

    // Once this is complete, we just need to wait for the data to come in.
}