socket编程之socket转串口

小咪咪 2022-07-18 20:59 369阅读 0赞

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系统环境：Centos 6.5

开发板：s3c2440

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1、程序功能

该程序是一个运行在开发板上的client程序，连接到windows下usr-tcp调试工具模拟的server，接受串口和socket数据并转发

usr-tcp通过tcp服务器向client发送数据，client接受到数据后通过串口发回usr-tcp

usr-tcp通过串口向client发送数据，client接收到数据后通过socket发回usr-tcp

![SouthEast][]

![Center][]

2、源代码

串口相关设置 serial.c

/*********************************************************************************
     *      Copyright:  (C) 2016 Lu Zengmeng<1540999272@qq.com>
     *                  All rights reserved.
     *
     *       Filename:  serial.c
     *    Description:  This file 
     *                 
     *        Version:  1.0.0(08/01/2016)
     *         Author:  Lu Zengmeng <1540999272@qq.com>
     *      ChangeLog:  1, Release initial version on "08/01/2016 06:44:59 PM"
     *                 
     ********************************************************************************/
    #include <stdio.h>
    #include <termios.h>
    #include <fcntl.h>
    #include <string.h>
    
    #define FAIL -1
    #define OK   0
     
    int speed_arr[] = {B115200,B57600,B38400,B19200,B9600,B4800,B2400,B1200,B600,B300,B110};
    int name_arr[]  = { 115200, 57600, 38400, 19200, 9600, 4800, 2400, 1200, 600, 300, 110};
    
    /* set baud rate */
    void set_speed(int fd, int speed)
    {
        int i;
        int status;
        struct termios options;
    
        tcgetattr(fd, &options);
        options.c_iflag &= ~ (INLCR | ICRNL | IGNCR);
        options.c_oflag &= ~(ONLCR | OCRNL);
        options.c_iflag &= ~(IXON);
    
        for( i= 0; i < sizeof(speed_arr) / sizeof(int); i++)
        {
            if(speed == name_arr[i])
            {
                tcflush(fd, TCIOFLUSH);/*empty input cache*/
    
                cfsetispeed(&options, speed_arr[i]);
                cfsetospeed(&options, speed_arr[i]);
    
                status = tcsetattr(fd, TCSANOW, &options);
                if(status != 0)
                       perror("tcsetattr fd");
    
                return;
            }
            tcflush(fd,TCIOFLUSH);/*empty input cache*/
        }
    }
    
    
    /**
     * *@brief 设置串口数据位，停止位和效验位
     * *@param fd 类型 int 打开的串口文件描述符
     * *@param databits 类型 int 数据位 取值 为 7 或者8
     * *@param stopbits 类型 int 停止位 取值为 1 或者2
     * *@param parity 类型 int 效验类型 取值为N,E,O,S
     * */
    int set_parity(int fd,int databits,int stopbits,int parity)
    {
        struct termios options;
        if ( tcgetattr( fd,&options) != 0)
        {
            perror("SetupSerial 1");
            return(FAIL);
        }
        options.c_cflag &= ~CSIZE;
        options.c_lflag  &= ~(ICANON | ECHO | ECHOE | ISIG);  /*Input*/
        options.c_oflag  &= ~OPOST;   /*Output*/
    
        switch (databits) /*set datebits*/
        {
            case 7:
                options.c_cflag |= CS7;
                break;
            case 8:
                options.c_cflag |= CS8;
                break;
            default:
                fprintf(stderr,"Unsupported data size\n");
                return (FAIL);
        }
    
        switch (parity)
        {
            case 'n':
            case 'N':
                options.c_cflag &= ~PARENB; /* Clear parity enable */
                options.c_iflag &= ~INPCK; /* Enable parity checking */
                break;
            case 'o':
            case 'O':
                options.c_cflag |= (PARODD | PARENB); /* 设置为奇效验*/
                options.c_iflag |= INPCK; /* Disnable parity checking */
                break;
            case 'e':
            case 'E':
                options.c_cflag |= PARENB; /* Enable parity */
                options.c_cflag &= ~PARODD; /* 转换为偶效验*/
                options.c_iflag |= INPCK; /* Disnable parity checking */
                break;
            case 'S':
            case 's': /*as no parity*/
                options.c_cflag &= ~PARENB;
                options.c_cflag &= ~CSTOPB;
                break;
            default:
                fprintf(stderr,"Unsupported parity\n");
                return (FAIL);
        }
        /*set stopbits */
        switch (stopbits)
        {
            case 1:
                options.c_cflag &= ~CSTOPB;
                break;
            case 2:
                options.c_cflag |= CSTOPB;
                break;
            default:
                fprintf(stderr,"Unsupported stop bits\n");
                return (FAIL);
        }
        /* Set input parity options */
        if (parity != 'n')
            options.c_iflag |= INPCK;
    
        options.c_cc[VTIME] = 0; // 15 seconds
        options.c_cc[VMIN] = 0;
    
        tcflush(fd,TCIFLUSH); /* Update the optionsions and do it NOW */
    
        if (tcsetattr(fd,TCSANOW,&options) != 0)
        {
            perror("tcsetattr");
            return FAIL;
        }
        return (OK);
    }
    /**
     * *@breif open device
     * */
    int open_dev(char *dev)
    {
        int fd;
    
        fd = open( dev, O_RDWR|O_NOCTTY|O_NDELAY);
        if (fd < 0)
        {
            perror("open");
            return FAIL;
        }
        else
            return fd;
    }

serial.h

/********************************************************************************
     *      Copyright:  (C) 2016 Lu Zengmeng<1540999272@qq.com>
     *                  All rights reserved.
     *
     *       Filename:  serial.h
     *    Description:  This head file 
     *
     *        Version:  1.0.0(08/01/2016)
     *         Author:  Lu Zengmeng <1540999272@qq.com>
     *      ChangeLog:  1, Release initial version on "08/01/2016 06:44:25 PM"
     *                 
     ********************************************************************************/
    #include <stdio.h>
    
    #ifndef __SERIAL_H__
    #define __SERIAL_H__
    
    extern int speed_arr[];
    extern int name_arr[];
    extern void set_speed(int fd, int speed);
    extern int set_parity(int fd,int databits,int stopbits,int parity);
    extern int open_dev(char *dev);
    
    #endif

socket初始化连接 tcp.c

tcp.h

/********************************************************************************
     *      Copyright:  (C) 2016 Lu Zengmeng<1540999272@qq.com>
     *                  All rights reserved.
     *
     *       Filename:  tcp.h
     *    Description:  This head file 
     *
     *        Version:  1.0.0(08/02/2016)
     *         Author:  Lu Zengmeng <1540999272@qq.com>
     *      ChangeLog:  1, Release initial version on "08/02/2016 08:22:06 AM"
     *                 
     ********************************************************************************/
    #include <stdio.h>
    
    #ifndef __TCP_H_
    #define __TCP_H_
    
    #define PORT             8003
    #define IPADDR           "192.168.1.104"
    extern int socket_init(void);
    
    #endif

main.c

/*********************************************************************************
     *      Copyright:  (C) 2016 Lu Zengmeng<1540999272@qq.com>
     *                  All rights reserved.
     *
     *       Filename:  main.c
     *    Description:  This file 
     *                 
     *        Version:  1.0.0(08/01/2016)
     *         Author:  Lu Zengmeng <1540999272@qq.com>
     *      ChangeLog:  1, Release initial version on "08/01/2016 06:45:37 PM"
     *                 
     ********************************************************************************/
    #include <stdio.h>
    #include <stdlib.h>  
    #include <string.h>  
    #include <errno.h> 
    #include <unistd.h>  
    
    #include <sys/types.h>  
    #include <sys/stat.h>  
    
    #include <fcntl.h>   
    #include <termios.h> 
    #include <pthread.h> 
    
    #include "serial.h" 
    #include "tcp.h" 
    
    #define  DEVICE      "/dev/ttyS1"
    #define  BUF_SIZE    128
    
    int    usrt_fd;
    int    sock_fd;
    
    void usrt_to_socket (void);
    void socket_to_usrt (void);
    
    /* start main */
    int main(int argc,char **argv)
    {
        int    ret;
        char   *dev = DEVICE;
        pthread_t sock,usrt;
    
        sock_fd = socket_init();
        usrt_fd = open_dev(dev);
    
        set_parity(usrt_fd,8,1,'N'); // 设置串口数据位、停止位、校验位
        set_speed(usrt_fd,9600); // 设置串口波特率
    
        ret = pthread_create(&sock,NULL,(void *)socket_to_usrt,NULL); // 创建sock线程接收socket数据
        if(ret < 0)
        {
            perror("phread_create");
            exit(1);
        }
    
        ret = pthread_create(&usrt,NULL,(void *)usrt_to_socket,NULL); // 创建usrt线程接收串口数据
        if(ret < 0)
        {
            perror("phread_create");
            exit(1);
        }
    
        pthread_join(sock,NULL); // 等待线程退出
        pthread_join(usrt,NULL);
    
        close(sock_fd);
        close(usrt_fd);
    
        printf("main exit...\n");
        return 0;
    }
    
    
    /**************************************************************************************
     *  Description:接收socket数据并通过串口转发
     *   Input Args:
     *  Output Args:
     * Return Value:
     *************************************************************************************/
    void socket_to_usrt (void)
    {
        printf("start socket_to_usrt...\n");
        int     n = 0;
        int     m = 0;
        char    buf[BUF_SIZE];
    
        while(1)
        {
            memset(buf,0,BUF_SIZE);
            n = read(sock_fd,buf,BUF_SIZE);
            if(n>0)
            {
                if(0==strncmp(buf,"exit",4)) // 收到exit时，线程退出
                {
                    m = write(usrt_fd,buf,BUF_SIZE);
                    if(m<0)
                    {
                        perror("write to usrt");
                    }
                    break;
                }
    
                m = write(usrt_fd,buf,BUF_SIZE);
                if(m<0)
                {
                    perror("write to usrt");
                }
            }
            else if(n<0)
            {
                perror("read from socket");
            }
        }
    
        printf("socket_to_usrt exit...\n");
        pthread_exit(0);
    } /* ----- End of sock_to_usrt()  ----- */
    
    
    /**************************************************************************************
     *  Description:接收串口数据并通过socket转发
     *   Input Args:
     *  Output Args:
     * Return Value:
     *************************************************************************************/
    void usrt_to_socket (void)
    {
        printf("start usrt_to_socket...\n");
        int     n = 0;
        int     m = 0;
        char    buf[BUF_SIZE];
    
        while(1)
        {
            memset(buf,0,BUF_SIZE);
            n = read(usrt_fd,buf,BUF_SIZE);
            if(n>0)
            {
                if(0==strncmp(buf,"exit",4)) // 收到exit时，线程退出
                {
                    m = write(sock_fd,buf,BUF_SIZE);
                    if(m<0)
                    {
                        perror("write to sock");
                    }
                    break;
                }
    
                m = write(sock_fd,buf,BUF_SIZE);
                if(m<0)
                {
                    perror("write to sock");
                }
            }
    
            else if(n<0)
            {
                perror("read from usrt");
            }
        }
        
        printf("usrt_to_socket exit...\n");
        pthread_exit(0);
    } /* ----- End of usrt_to_sock()  ----- */

makefile

NAME=client
    CC=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-gcc
    EXTRA_CFLAGS+= -Wall -Werror
    EXTRA_CFLAGS+= -lpthread
    all:
            $(CC) $(EXTRA_CFLAGS) main.c serial.c tcp.c -o $(NAME)
            cp $(NAME) /tftp

3、调试助手下载

[USR-TCP232-Test][]

[SouthEast]: /images/20220718/93319ada3c5841f29c2df7af9dadb6bc.png
[Center]: /images/20220718/17267057abac4650b123ebde40f92361.png
[USR-TCP232-Test]: http://www.usr.cn/Download/27.html