linux 调整串口波特率

# 查看当前串口设置
stty -F /dev/ttyS0

# 设置波特率为9600
stty -F /dev/ttyS0 ispeed 9600 ospeed 9600 cs8 -cstopb -parenb

# 设置波特率为115200
stty -F /dev/ttyS0 ispeed 115200 ospeed 115200 cs8 -cstopb -parenb

# 查看串口信息
setserial -g /dev/ttyS0

# 设置波特率
setserial /dev/ttyS0 spd_cust baud_base 115200

sudo stty -F /dev/ttyS0 ispeed 115200 ospeed 115200 cs8 -cstopb -parenb

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <termios.h>

int set_interface_attribs(int fd, int speed, int parity) {
    struct termios tty;
    memset(&tty, 0, sizeof(tty));
    if (tcgetattr(fd, &tty) != 0) {
        perror("error from tcgetattr");
        return -1;
    }

    cfsetospeed(&tty, speed);
    cfsetispeed(&tty, speed);

    tty.c_cflag = (tty.c_cflag & ~CSIZE) | CS8;     // 8-bit 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[VTIME] = 0;            // inter-character timer unused
    tty.c_cc[VMIN] = 1;             // block if waiting for char

    tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off s/w flow ctrl
    tty.c_cflag |= (CLOCAL | CREAD); // ignore modem controls, enable reading
    tty.c_cflag &= ~(PARENB | PARODD); // shut off parity
    tty.c_cflag |= parity;
    tty.c_cflag &= ~CSTOPB;
    tty.c_cflag &= ~CRTSCTS; // no HW flow ctrl

    if (tcsetattr(fd, TCSANOW, &tty) != 0) {
        perror("error from tcsetattr");
        return -1;
    }
    return 0;
}

int main() {
    int fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
    if (fd == -1) {
        perror("error opening /dev/ttyS0");
        return -1;
    }

    set_interface_attribs(fd, B115200, 0); // 设置波特率为115200，无校验

    char buf[100];
    while (1) {
        int n = read(fd, buf, sizeof(buf));
        if (n > 0) {
            write(STDOUT_FILENO, buf, n);
        }
    }

    close(fd);
    return 0;
}