serial port programming

QNX Newsgroups (Archives) qdn.public.qnxrtp.devtools
1

Hi

I’ve been trying to make a simple program to communicate with a
robot using RS-232, it seems like there’s 2 approches (correct me if I’m
wrong)
on low level is qnx_ioctl(), and the other using the termios strcuture.

I tried to implement the program shown in the Knowledge base, but I
encountered
problems, beacuse I don’t have the <sys/dev.h> header file, Is there a
problem with
my QNX installation? could someone point me into the right direction?

Any ideas/advice will be greatly appreciated.

Program listing:

#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <termios.h>
#include <sys/dev.h>
#include <sys/uio.h>

#define SERDEV1 “/dev/ser1”
#define BAUD 9600

int open_device (char *device);
void serial_device_init(int file_des);
void read_device (int file_des);

main()
{
int file_des;

file_des = open_device (SERDEV1);
serial_device_init (file_des);
for(;:wink:
read_device (file_des);
}

int open_device (char *device)
{
int file_des;
struct _dev_info_entry info;

if ((file_des = open(device, O_RDWR)) = -1{
printf(“error opening %s: %s\n”,
device, strerror(errno));
exit(1);
}
if(dev_info(file_des, &info) != -1)
printf(“NODE %d, TTY %d\n”, info.nid, info.tty);
else
printf(“dev_info failed\n”,strerror(errno));
return(file_des);
}
void serial_device_init(int file_des)
{
int i;
struct termios termios_p;
speed_t speed = BAUD;

// get the control structure for /dev/ser1

tcgetattr(file_des, &termios_p);

/* get control structure for /dev/ser1 */

// Set the baud (will he set with tcsetattr())

cfsetispeed(&termios_p, speed); // input
cfsetospeed(&termios_p, speed); // output

termios_p.c_cflag &= ~CSIZE;
termios_p.c_cflag |= CS8|CREAD|PARENB;
termios_p.c_iflag |=PARMRK | INPCK;
termios_p.c_iflag &= ~IGNPAR;

// disable all control characters in the c_cc array

for (i = 0; i <NCCS; i++)
termios_p.c_cc _= PC_VDISABLE;

// Apply the settings immediately

tcsetattr(file_des, TCSANOW, &termios_p);
tcgetattr(file_des, &termios_p);

// Print out some status information

printf(“Input modes %lu\n”, termios_p.c_iflag);
printf(“Output modes %lu\n”, termios_p.c_oflag);
printf(“Control modes %lu\n”, termios_p.c_cflag);
printf(“Local modes %lu\n”, termios_p.c_lflag);
printf(“Device Status %d\n”, termios_p.c_status);
printf(“QNX spec flags %d\n”, termios_p.c_qflag);
}

void read_device (int file_des)
{
int bytes;
char readbuf[1]={0};
int i;

// Read from the serial port

if((bytes = dev_read(file_des, &readbuf,
1, 1, 0, 0, 0, NULL)) = -1)
printf(“error on dev_read %s\n”, strerror(errno));
else{
printf(“bytes read is %d\n”, bytes);
for (i=0; i<bytes; i++)
printf("\tbyte_read = %o\n", readbuf, i);
}

2

I am attempting a similar task, the QNX help states that dev_read is a qnx4
routine the Neutrino equilvalent is readcond, is you cut out the dev_
routines then you shouldn’t need <sys/dev.h>

My problem is that I cannot receive any data from the serial port, if you
figure out the correct settings for termios, please let me know. I am
trying to configure the port for raw read and write access.

“Hugo Ordoñez” <hugoj@cee.hw.ac.uk> wrote in message
news:9auni9$5eg$1@inn.qnx.com…

Hi

I’ve been trying to make a simple program to communicate with a
robot using RS-232, it seems like there’s 2 approches (correct me if I’m
wrong)
on low level is qnx_ioctl(), and the other using the termios strcuture.

I tried to implement the program shown in the Knowledge base, but I
encountered
problems, beacuse I don’t have the <sys/dev.h> header file, Is there a
problem with
my QNX installation? could someone point me into the right direction?

Any ideas/advice will be greatly appreciated.

Program listing:

#include <string.h
#include <errno.h
#include <fcntl.h
#include <unistd.h
#include <stdlib.h
#include <stdio.h
#include <termios.h
#include <sys/dev.h
#include <sys/uio.h

#define SERDEV1 “/dev/ser1”
#define BAUD 9600

int open_device (char *device);
void serial_device_init(int file_des);
void read_device (int file_des);

main()
{
int file_des;

file_des = open_device (SERDEV1);
serial_device_init (file_des);
for(;:wink:
read_device (file_des);
}

int open_device (char *device)
{
int file_des;
struct _dev_info_entry info;

if ((file_des = open(device, O_RDWR)) = -1{
printf(“error opening %s: %s\n”,
device, strerror(errno));
exit(1);
}
if(dev_info(file_des, &info) != -1)
printf(“NODE %d, TTY %d\n”, info.nid, info.tty);
else
printf(“dev_info failed\n”,strerror(errno));
return(file_des);
}
void serial_device_init(int file_des)
{
int i;
struct termios termios_p;
speed_t speed = BAUD;

// get the control structure for /dev/ser1

tcgetattr(file_des, &termios_p);

/* get control structure for /dev/ser1 */

// Set the baud (will he set with tcsetattr())

cfsetispeed(&termios_p, speed); // input
cfsetospeed(&termios_p, speed); // output

termios_p.c_cflag &= ~CSIZE;
termios_p.c_cflag |= CS8|CREAD|PARENB;
termios_p.c_iflag |=PARMRK | INPCK;
termios_p.c_iflag &= ~IGNPAR;

// disable all control characters in the c_cc array

for (i = 0; i <NCCS; i++)
termios_p.c_cc > _= PC_VDISABLE;

// Apply the settings immediately

tcsetattr(file_des, TCSANOW, &termios_p);
tcgetattr(file_des, &termios_p);

// Print out some status information

printf(“Input modes %lu\n”, termios_p.c_iflag);
printf(“Output modes %lu\n”, termios_p.c_oflag);
printf(“Control modes %lu\n”, termios_p.c_cflag);
printf(“Local modes %lu\n”, termios_p.c_lflag);
printf(“Device Status %d\n”, termios_p.c_status);
printf(“QNX spec flags %d\n”, termios_p.c_qflag);
}

void read_device (int file_des)
{
int bytes;
char readbuf[1]={0};
int i;

// Read from the serial port

if((bytes = dev_read(file_des, &readbuf,
1, 1, 0, 0, 0, NULL)) = -1)
printf(“error on dev_read %s\n”, strerror(errno));
else{
printf(“bytes read is %d\n”, bytes);
for (i=0; i<bytes; i++)
printf("\tbyte_read = %o\n", readbuf> , i);
}