handle mavlink packets

def idle_task(self):
        '''handle mavlink packets'''
        if not self.started:
            return
        now = time.time()
        if now - self.last_packet < 1:
            timeout = 0.05
        else:
            timeout = 0.2
        if now - self.last_check > timeout:
            self.last_check = now
            mav = self.master.mav
            flags = mavutil.mavlink.SERIAL_CONTROL_FLAG_RESPOND
            flags |= mavutil.mavlink.SERIAL_CONTROL_FLAG_MULTI
            flags |= mavutil.mavlink.SERIAL_CONTROL_FLAG_EXCLUSIVE
            mav.serial_control_send(self.serial_settings.port,
                                    flags,
                                    0, self.serial_settings.baudrate,
                                    0, [0]*70)