本文共 1811 字，大约阅读时间需要 6 分钟。

1，打开串口

      /**打开串口，dev 串口设备名， mode 打开方式，**/

int opendev(char *dev,mode_t mode)

    {           int fd;           fd = open(dev, mode);           if (-1 == fd){                    perror("Can't Open Serial Port");                 return -1;            }           else{                  fcntl(fd, F_SETFL, FNDELAY);                  return fd;           }      }

2，写串口

    #define FALSE  -1

    #define TRUE   0     #define NET_PORT 19988     #define MAX_BUF_SIZE 4096     struct net2net_buf{            int len;            char buf[MAX_BUF_SIZE];      };

     #define RSDEV_NAME "/dev/ttyS1"

     int main(void)

     {             int rsfd = 0;             int nwrite;             char input_buf[64];             rsfd = opendev(RSDEV_NAME,O_RDWR | O_NOCTTY | O_NDELAY);             if(rsfd < 0){                   printf("open error:/n");                   exit(-1);             }             set_speed(rsfd,9600);    /*设置速率B9600*/             if (set_parity(rsfd,8,1,'N') == FALSE){ /*8位数据位，一位停止位*/                    printf("Set Parity Error/n");                    exit (-1);             }             while(1)

           {

                   fgets(input_buf,sizeof(input_buf),stdin);                    printf("input_buf = %s", input_buf);                    nwrite = write(rsfd, input_buf, strlen(input_buf));                    if ( nwrite == -1 ) {                         perror("ERROR!");                         exit(1);                    }

                   else {

                        printf("ret=%d/n", nwrite);                    }             }        }

3，读串口

      int read_rs232(int rsfd)

      {              int     retbytes = 0,nread = 0;              int all_bytes = 0;              struct  net2net_buf netbuf;              int i;              memset(&netbuf,0,sizeof(netbuf));              while((nread = read(rsfd, &netbuf.buf[retbytes], 512))>0)              {                     printf("nread:%d/n",nread);                     retbytes += nread;                     all_bytes  += nread;               }               return all_bytes;         }         int main(void)        {               int rsfd = 0;               int nwrite;               fd_set  fdR;               struct timeval  timev;               int n = 0;               char input_buf[64];               rsfd = opendev(RSDEV_NAME,O_RDWR | O_NOCTTY | O_NDELAY);               if(rsfd < 0){                    printf("open error:/n");                    exit(-1);               }               set_speed(rsfd,9600);    /*设置速率B9600*/               if (set_parity(rsfd,8,1,'N') == FALSE){ /*8位数据位，一位停止位*/                     printf("Set Parity Error/n");                     exit (-1);               }               while(1) {                     FD_ZERO(&fdR);                     FD_SET(rsfd, &fdR);                     timev.tv_sec  = 0;                     timev.tv_usec = 100000;                     n = select(rsfd+1, &fdR, NULL, NULL, &timev);                     if(n <= 0)                          continue;                     if (FD_ISSET(rsfd,&fdR)) {                          printf("rs232 recv/n");                          read_rs232(rsfd);                     }                }         }

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