UART 0x0D变为0x0A

Question

以下代码在BeagleBone Black上配置两个UART端口。

// Open the given file as read/write, don't become the controlling terminal, don't block
    int fileDescriptor = open(filename, O_RDWR | O_NOCTTY | O_SYNC);

    if(fileDescriptor == -1) {
        cerr << "open_port: Unable to open " << filename << " " << strerror(errno) << endl;
        return false;
    }

    struct termios tty;

    memset(&tty, 0, sizeof tty);

    if(tcgetattr(fileDescriptor, &tty) != 0) {
        cerr << strerror(errno) << endl;
        return false;
    }

    // Baud
    cfsetispeed(&tty, B115200);
    cfsetospeed(&tty, B115200);

    // 8-bit chars
    tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8;

    // Disable IGNBRK for mismatched speed tests; otherwise receive break
    // as \000 chars
    tty.c_iflag &= ~IGNBRK;         // disable break processing
    tty.c_lflag = 0;                // no signaling chars, no echo

    // No canonical processing
    tty.c_oflag = 0;                // no remapping, no delays
    tty.c_cc[VMIN]  = 0;            // read doesn't block
    tty.c_cc[VTIME] = 5;            // 0.5 seconds read timeout

    // Shut off xon/xoff ctrl
    tty.c_iflag &= ~(IXON | IXOFF | IXANY);

    // Ignore modem controls
    tty.c_cflag |= (CLOCAL | CREAD);

    // Enable reading
    tty.c_cflag &= ~(PARENB | PARODD);      // shut off parity
    tty.c_cflag |= 0;
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS;

    if(tcsetattr(fileDescriptor, TCSANOW, &tty) != 0) {
        cerr << strerror(errno) << endl;
        return false;
    }

我能够发送数据，但由于某种原因，发送的0x0D被接收为0x0A＆＃39; s。我非常确定此端口配置中的某些内容正在执行此操作。

Answer 1

我注意到man page for tcsetattr上的这三个标志：

INLCR

Translate NL to CR on input.

IGNCR

Ignore carriage return on input.

ICRNL

Translate carriage return to newline on input (unless IGNCR is set).

您可能想尝试将INLCR和ICRNL明确设置为0？