Half duplex komunikacijaDakle, imam problem sa half duplex komunikacijom po linuxom...
Izvorni kod preuzet od nekog howto manuala
Code:
#include <stdio.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <termios.h>
#include <stdlib.h>
struct termios tio;
int main()
{
int fd, status, whichBaud, result,i;
long baud;
char buffer[255];
varijabla[2] = "\x31\x31";
baud = B9600;
fd = open(device ,O_RDWR | O_NOCTTY);
if (fd <0)
{
printf("error");
exit(1);
}
tio.c_cflag = baud | CS8 | CREAD | CLOCAL;
tio.c_iflag = IGNPAR; /* ignore parity errors */
tio.c_oflag = 0; /* set output flag non-canonical, no processing */
tio.c_cc[VTIME] = 18; /* no time delay */
tio.c_cc[VMIN] = 0; /* no char delay */
tcflush(fd, TCIFLUSH); /* flush the buffer */
tcsetattr(fd, TCSANOW, &tio); /* set the attributes *
/* Set up for no delay, ie non-blocking reads will occur.
When we read, we'll get what's in the input buffer or nothing */
fcntl(fd, F_SETFL, FNDELAY);
write(fd,varijabla,2);
result = read(fd,buffer,255);
printf("%c\n",result);
buffer[result] = 0; // zero terminate so printf works
printf("%s\n",buffer);
}
/* close the device file */
close(fd);
#include <stdio.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <termios.h>
#include <stdlib.h>
struct termios tio;
int main()
{
int fd, status, whichBaud, result,i;
long baud;
char buffer[255];
varijabla[2] = "\x31\x31";
baud = B9600;
fd = open(device ,O_RDWR | O_NOCTTY);
if (fd <0)
{
printf("error");
exit(1);
}
tio.c_cflag = baud | CS8 | CREAD | CLOCAL;
tio.c_iflag = IGNPAR; /* ignore parity errors */
tio.c_oflag = 0; /* set output flag non-canonical, no processing */
tio.c_cc[VTIME] = 18; /* no time delay */
tio.c_cc[VMIN] = 0; /* no char delay */
tcflush(fd, TCIFLUSH); /* flush the buffer */
tcsetattr(fd, TCSANOW, &tio); /* set the attributes *
/* Set up for no delay, ie non-blocking reads will occur.
When we read, we'll get what's in the input buffer or nothing */
fcntl(fd, F_SETFL, FNDELAY);
write(fd,varijabla,2);
result = read(fd,buffer,255);
printf("%c\n",result);
buffer[result] = 0; // zero terminate so printf works
printf("%s\n",buffer);
}
/* close the device file */
close(fd);
Ovdje kad posaljem varijablu "31 31" trebao bih dobiti odgovor od 18 bytova.
Primim je i sve radi OK, ali ako ne primim 18 bytova program ceka u nedogled.
Moze li se namjestit recimo, ako se ne pojavi nista na portu u 200 ms...prekini sa cekanjem tih 18 bytova nego posalji opet varijablu?
There are 10 types of people in the world:
Those who understand binary and those who don't.
Those who understand binary and those who don't.
