noncanonical.c

/*Non-Canonical Input Processing*/

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <stdio.h>

#define BAUDRATE B38400
#define _POSIX_SOURCE 1 /* POSIX compliant source */
#define MODEMDEVICE "/dev/ttyS0"
#define FALSE 0
#define TRUE 1

#define F 0x7e
#define A 0x03
#define S 0x03
#define U 0x07

//volatile int STOP=FALSE;

int main(int argc, char** argv)
{
    int fd,c, res;
    struct termios oldtio,newtio;
    char buf[255];
    char SET[255];
    unsigned char ua[5];
/*
    if ( (argc < 2) ||
         ((strcmp("/dev/ttyS0", argv[1])!=0) &&
          (strcmp("/dev/ttyS1", argv[1])!=0) )) {
      printf("Usage:\tnserial SerialPort\n\tex: nserial /dev/ttyS1\n");
      exit(1);
    }

*/
  /*
    Open serial port device for reading and writing and not as controlling tty
    because we don't want to get killed if linenoise sends CTRL-C.
  */

    system ("clear");

    fd = open(MODEMDEVICE, O_RDWR | O_NOCTTY );
    if (fd <0) {perror(argv[1]); exit(-1); }

    if ( tcgetattr(fd,&oldtio) == -1) { /* save current port settings */
      perror("tcgetattr");
      exit(-1);
    }

    bzero(&newtio, sizeof(newtio));
    newtio.c_cflag = BAUDRATE | CS8 | CLOCAL | CREAD;
    newtio.c_iflag = IGNPAR;
    newtio.c_oflag = 0;

    /* set input mode (non-canonical, no echo,...) */
    newtio.c_lflag = 0;

    newtio.c_cc[VTIME]    = 0;   /* inter-character timer unused */
    newtio.c_cc[VMIN]     = 1;   /* blocking read until 1 chars received */


  /*
    VTIME e VMIN devem ser alterados de forma a proteger com um temporizador a
    leitura do(s) próximo(s) caracter(es)
  */



    tcflush(fd, TCIOFLUSH);

    if ( tcsetattr(fd,TCSANOW,&newtio) == -1) {
      perror("tcsetattr");
      exit(-1);
    }

    printf("New termios structure set\n");

    int aux = 0, state = 0;
    while (state < 5)
    {
    res = read(fd,buf,1);
    printf("%x - %d\n", buf[0], res);
    switch (state)
    {
        case 0:
            if (buf[0] == F)
            {
                SET[state] = buf[0];
                state++;
            }
            break;
        case 1:
            if (buf[0] == A)
            {
                SET[state] = buf[0];
                state++;
            }
            else if (buf[0] != F && buf[0] != A)
                state--;
            break;
        case 2:
            if (buf[0] == S)
            {
                SET[state] = buf[0];
                state++;
            }
            else if (buf[0] == F)
                state--;
            else
                state = 0;
            break;
        case 3:
            if (buf[0] == (A ^ S))
            {
                SET[state] = buf[0];
                state++;
            }
            else if (buf[0] == F)
                state = 1;
            else
                state = 0;
            break;
        case 4:
            if (buf[0] == F)
            {
                SET[state] = buf[0];
                state++;
            }
            else
                state = 0;
            break;
    }
    }

    printf ("Printing SET:\n");
    int i=0;
    for(i; i < state; i++)
        printf("%x", SET[i]);
    printf("\n");

    ua[0] = F;
    ua[1] = A;
    ua[2] = U;
    ua[3] = (A ^ U);
    ua[4] = F;

    res = write(fd, ua, 5);
    printf("%d bytes written\n",res);


    tcsetattr(fd,TCSANOW,&oldtio);
    close(fd);
    return 0;
}