M的部落格

reference:

http://shyuanliang.blogspot.tw/2011/01/rs232-read-write.html

http://nigelzeng.iteye.com/blog/1533141

content:

#include <pthread.h>
#include <stdio.h>
#include <termios.h>
#include <fcntl.h>
#include <string.h>
#include <sys/select.h>

#define BUFFER_SIZE 100
#define REQ_INFO 0x12
#define REQ_NA 0x00

char* Message="Hello1 Hello2 Hello3 Hello4 Hello5 Hello6 Hello7 Hello8 Hello9 Hello10";
char incomingBuffer[BUFFER_SIZE];
int fd1;
int fd2;
char csReq[100];//={0x12,0x00};

void* ReaderThread(void* object)
{

     int total=0;
     int expected=strlen(Message);
     struct timeval timeOut;
     fd_set fdSet;
     int maxFdp=0;

     printf("Waiting for data on serial ports\r\n");
     printf("total =%d, expected = %d \r\n", total, expected);

     while(total<100)
     {
          timeOut.tv_sec=0;
          timeOut.tv_usec=100000; // Every 100 ms
          FD_ZERO(&fdSet);
          FD_SET(fd1, &fdSet);
       //   FD_SET(fd2, &fdSet);
          maxFdp=fd1+1;
          int result=select(maxFdp, &fdSet, (fd_set*)0, (fd_set*)0, &timeOut);

          if(result<0) {
               printf("A select error occured.. exiting\r\n");
               exit(-1);
          }
          else if(result>0)
          {
               printf("Data is available on a port\r\n");
               int n=0;
               if(FD_ISSET(fd1, &fdSet)) {
                   n=read(fd1, incomingBuffer, BUFFER_SIZE);
                   printf("Data is available on a port  ttyS1 \r\n");
               }
            //   else if(FD_ISSET(fd2, &fdSet)) {
             //       n=read(fd2, incomingBuffer, BUFFER_SIZE);
             //       printf("Data is available on a port  ttyS3  \r\n");
             //  }
               else {
                    printf("Unexpected fd from select... exiting\r\n");
                    exit(-1);
               }
               incomingBuffer[n]='\0';
                int i=strlen(incomingBuffer);
                int j=0;
                for(j=0;j<i;j++)
                        printf("Received: 0x%x\r\n", incomingBuffer[j]);
               //total+=n;
                total++;
          }
          // else (result==0) just a time out so go round again
     }

      return 0;
}

int OpenPort(const char* port)
{
     printf("Opening serial %s\r\n", port);
     int fd=open(port, O_RDWR | O_NOCTTY );
     if(fd==-1)
     {
          printf("Error opening serial port %s... exiting", port);
          return -1;
     }
     fcntl(fd, F_SETOWN/*F_SETFL*/, 0); /* Reads will be blocking */

     struct termios options;
     bzero((char*)&options, sizeof(options));
    // tcgetattr(fd, &options);
    // (void)cfsetispeed(&options, B115200); /* (void) is to stop warning in cygwin */
    // (void)cfsetospeed(&options, B115200);
    // options.c_cflag &= ~CSIZE;

    // options.c_cflag |= CS8;  /* 8 bits */

    // options.c_cflag &= ~CSTOPB; /* 1 stop bit */

//     options.c_cflag &= ~PARENB; /* no parity */
//     options.c_cflag &= ~PARODD;

        options.c_cflag = B115200 | CS8 | CLOCAL | CREAD;


//     options.c_cflag &= ~CRTSCTS; /* HW flow control off */

//     options.c_cflag |= (CLOCAL | CREAD);

    options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); //= 0; /* RAW input */
     options.c_iflag = 0;            /* SW flow control off, no parity checks etc */
     options.c_oflag = 0;//&= ~OPOST; /* RAW output */
     options.c_cc[VTIME]= 250;//0; //10; /* 1 sec */
     options.c_cc[VMIN]= 0; //BUFFER_SIZE;

     tcflush(fd, TCIFLUSH);
     tcsetattr(fd, TCSANOW, &options);

     return fd;
}

 int main(int argc, char** argv)
{
        int n=0;
     fd1=OpenPort("/dev/ttyS2");
 //    fd2=OpenPort("/dev/ttyS1"); // assuming fd2>fd1 in thread
    printf(" %d \r\n", isatty(fd1));
// Start thread to wait for incoming message on ttyS1
//     pthread_t tid;
//     pthread_create(&tid, (pthread_attr_t*)(0), &ReaderThread, (void*)(0));
     sleep(1);
//     memset(csReq, 0, sizeof(csReq));
//     csReq[0]=0x11;
//     csReq[1]=0x01;
//     csReq[2]='\0';
 //    printf("Sending reboot req..., %#x, %d \r\n", *csReq, strlen(csReq));
//     n=write(fd1, csReq, strlen(csReq));
//     printf("n=%d \r\n", n);

     memset(csReq, 0, sizeof(csReq));
     csReq[0]=0x12;
     csReq[1]=0x00;


     printf("Sending get local dev info..., %#x, %d \r\n", *csReq, strlen(csReq));

//     n=write(fd1, csReq, strlen(csReq));
//     printf("n=%d \r\n", n);

     n=write(fd1, csReq, 2);

     printf("n=%d \r\n", n);
   //  n=write(fd1, csReq[1], 1);
   //  printf("n=%d \r\n", n);
        
//     pthread_join(tid, (void*)(0));
//     printf("After sent... \r\n");

        if(!fd1)
        {
                printf(" fd1 is null!!\n");
                return 0;
        }
        int res;
        n=0;
        int j;
        char csRes[256];
        char Res;
        while(1)
        {
                printf("read - %d \n", n);
                res=read(fd1, csRes, 255);
                //res=read(fd1, Res, 1);
                if(res == 0)
                        continue;
                csRes[res]=0;

                //printf("%d, read : res=%d, csRes=%s \n",n, res,Res);
                printf("%d, read: res=%d, csRes=%s, sizeof(char) = %d \n", n, res, csRes, sizeof(char));
                for(j=0; j<res; j++)
                        printf("received: %#x \n", csRes[j]);
                n++;
                if(n > 100)
                        break;
        }

     close(fd1);
    // close(fd2);
     printf("End of main-thread \n");

     return 0;
}