This callback is called form the Crazyflie API when a Crazyflie
        has been connected and the TOCs have been downloaded.

def _connected(self, link_uri):
        """ This callback is called form the Crazyflie API when a Crazyflie
        has been connected and the TOCs have been downloaded."""
        print('Connected to %s' % link_uri)

        # The definition of the logconfig can be made before connecting
        self._lg_stab = LogConfig(name='Stabilizer', period_in_ms=10)
        self._lg_stab.add_variable('stabilizer.roll', 'float')
        self._lg_stab.add_variable('stabilizer.pitch', 'float')
        self._lg_stab.add_variable('stabilizer.yaw', 'float')

        # Adding the configuration cannot be done until a Crazyflie is
        # connected, since we need to check that the variables we
        # would like to log are in the TOC.
        try:
            self._cf.log.add_config(self._lg_stab)
            # This callback will receive the data
            self._lg_stab.data_received_cb.add_callback(self._stab_log_data)
            # This callback will be called on errors
            self._lg_stab.error_cb.add_callback(self._stab_log_error)
            # Start the logging
            self._lg_stab.start()
        except KeyError as e:
            print('Could not start log configuration,'
                  '{} not found in TOC'.format(str(e)))
        except AttributeError:
            print('Could not add Stabilizer log config, bad configuration.')

        # Start a timer to disconnect in 10s
        t = Timer(5, self._cf.close_link)
        t.start()