code: def _connected(self, link_uri):
          
          print('Connected to %s' % link_uri)
  
          mems = self._cf.mem.get_mems(MemoryElement.TYPE_1W)
          print('Found {} 1-wire memories'.format(len(mems)))
          if len(mems) > 0:
              print('Writing test configuration to'
                    ' memory {}'.format(mems[0].id))
  
              mems[0].vid = 0xBC
              mems[0].pid = 0xFF
  
              board_name_id = OWElement.element_mapping[1]
              board_rev_id = OWElement.element_mapping[2]
  
              mems[0].elements[board_name_id] = 'Test board'
              mems[0].elements[board_rev_id] = 'A'
  
              mems[0].write_data(self._data_written)
docs: This callback is called form the Crazyflie API when a Crazyflie
          has been connected and the TOCs have been downloaded.