// シリアル通信を行う
void writeBySerial(void)
{
    // 1回目の通信なら初期設定
    if(0 == config_counter){
        port.set_option(serial_port_base::baud_rate(38400));
        port.set_option(serial_port_base::character_size(8));
        port.set_option(serial_port_base::flow_control(serial_port_base::flow_control::none));
        port.set_option(serial_port_base::parity(serial_port_base::parity::none));
        port.set_option(serial_port_base::stop_bits(serial_port_base::stop_bits::one));
        config_counter++;
    }
        
    if(succeedS_R(port)){
        printf("S_R Handshake successfully done\n");
        if(sendImage(port)){
            printf("data correctly written\n");
        }
    }
    
    return;
}
    DriverComms(std::string port, int baudrate){

        sp = new serial_port(io);
        //connect to port
        sp->open(port, ec);
        if(ec)
        {
            //Failure to connect
            ROS_ERROR_STREAM("Error connecting to expression board: " << ec.message());
            sp->close();
            delete sp;
            throw std::exception();
        }

        //Set the baudrate
        sp->set_option(serial_port_base::baud_rate(baudrate));

    }