def cmd_dataflash_logger(self, args):
        '''control behaviour of the module'''
        if len(args) == 0:
            print (self.usage())
        elif args[0] == "status":
            print (self.status())
        elif args[0] == "stop":
            self.new_log_started = False
            self.stopped = True
        elif args[0] == "start":
            self.stopped = False
        elif args[0] == "set":
            self.log_settings.command(args[1:])
        else:
            print (self.usage())
control behaviour of the module