linux下c语言操作串口

[墨香年少 32]

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

// 函数声明
int open_serial(const char *device);
int setup_serial(int fd, int speed, int parity);
int serial_read(int fd, char *buf, int size);
int serial_write(int fd, const char *buf, int size);
void close_serial(int fd);

// 打开串口设备
int open_serial(const char *device) {
    int fd = open(device, O_RDWR | O_NOCTTY | O_SYNC);
    if (fd < 0) {
        perror("open_serial() failed");
        return -1;
    }
    return fd;
}

// 配置串口参数
int setup_serial(int fd, int speed, int parity) {
    struct termios tty;
    memset(&tty, 0, sizeof tty);
    if (tcgetattr(fd, &tty) != 0) {
        perror("setup_serial() failed");
        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[VMIN]  = 0;                            // read doesn't block
    tty.c_cc[VTIME] = 5;                            // 0.5 seconds read timeout

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

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

// 读取串口数据
int serial_read(int fd, char *buf, int size) {
    int n = read(fd, buf, size);
    if (n < 0) {
        perror("serial_read() failed");
        return -1;
    }
    return n;
}

// 向串口写入数据
int serial_write(int fd, const char *buf, int size) {
    int n = write(fd, buf, size);
    if (n < 0) {
        perror("serial_write() failed");
        return -1;
    }
    return n;
}

// 关闭串口设备
void close_serial(int fd) {
    close(fd);
}

// 主函数示例
int main() {
    int fd = open_serial("/dev/ttyUSB0"); // 替换为实际的串口设备文件
    if (fd < 0) return 1;

    if (setup_serial(fd, B9600, 0) < 0) { // 设置波特率为 9600
        close_serial(fd);
        return 1;
    }

    const char *msg = "Hello, serial port!";
    serial_write(fd, msg, strlen(msg)); // 发送数据

    char buf[100];
    int n = serial_read(fd, buf, sizeof(buf) - 1); // 读取数据
    if (n >= 0) {
        buf[n] = '\0';
        printf("Received: %s\n", buf);
    }

    close_serial(fd);
    return 0;
}