def serial_send(self, args):
        '''send some bytes'''
        mav = self.master.mav
        flags = 0
        if self.locked:
            flags |= mavutil.mavlink.SERIAL_CONTROL_FLAG_EXCLUSIVE
        if self.serial_settings.timeout != 0:
            flags |= mavutil.mavlink.SERIAL_CONTROL_FLAG_RESPOND
        if self.serial_settings.timeout >= 500:
            flags |= mavutil.mavlink.SERIAL_CONTROL_FLAG_MULTI

        s = ' '.join(args)
        s = s.replace('\\r', '\r')
        s = s.replace('\\n', '\n')
        buf = [ord(x) for x in s]
        buf.extend([0]*(70-len(buf)))
        mav.serial_control_send(self.serial_settings.port,
                                flags,
                                self.serial_settings.timeout,
                                self.serial_settings.baudrate,
                                len(s), buf)