我已经解决了我的问题，所以我在这里发布了正确的代码，以防有人需要类似的东西。
开放港口
int USB = open( "/dev/ttyUSB0", O_RDWR| O_NOCTTY );
设定参数
struct termios tty;struct termios tty_old;memset (&tty, 0, sizeof tty);if ( tcgetattr ( USB, &tty ) != 0 ) { std::cout << "Error " << errno << " from tcgetattr: " << strerror(errno) << std::endl;}tty_old = tty;cfsetospeed (&tty, (speed_t)B9600);cfsetispeed (&tty, (speed_t)B9600);tty.c_cflag &= ~PARENB; // Make 8n1tty.c_cflag &= ~CSTOPB;tty.c_cflag &= ~CSIZE;tty.c_cflag |= CS8;tty.c_cflag &= ~CRTSCTS;// no flow controltty.c_cc[VMIN] = 1; // read doesn't blocktty.c_cc[VTIME] = 5; // 0.5 seconds read timeouttty.c_cflag |= CREAD | CLOCAL; // turn on READ & ignore ctrl linescfmakeraw(&tty);tcflush( USB, TCIFLUSH );if ( tcsetattr ( USB, TCSANOW, &tty ) != 0) { std::cout << "Error " << errno << " from tcsetattr" << std::endl;}写
unsigned char cmd[] = "INIT r";int n_written = 0, spot = 0;do { n_written = write( USB, &cmd[spot], 1 ); spot += n_written;} while (cmd[spot-1] != 'r' && n_written > 0);绝对没有必要每个字节写一个字节，也可以正常
int n_written = write( USB, cmd, sizeof(cmd) -1)工作。
最后， 阅读 ：
int n = 0, spot = 0;char buf = ' ';char response[1024];memset(response, ' ', sizeof response);do { n = read( USB, &buf, 1 ); sprintf( &response[spot], "%c", buf ); spot += n;} while( buf != 'r' && n > 0);if (n < 0) { std::cout << "Error reading: " << strerror(errno) << std::endl;}else if (n == 0) { std::cout << "Read nothing!" << std::endl;}else { std::cout << "Response: " << response << std::endl;}这个为我工作。谢谢你们！
