Serial port not working from Linux -> QNX

QNX DEVELOPERS Porting
1

In porting an application from Linux RedHat 7.2 to QNX Neutrino the serial port is no longer working. It is behaving as though the speed is not set correctly (as in, I still can send / receive data, but it just isn’t correct).

Here is my setup code:

char portName [] = “/dev/ser1”;

sd = open(portName, O_RDWR | O_NOCTTY);
if (sd < 0) {
perror(portName);
exit(-1);
}

tcgetattr(sd, &oldtio); // save current serial port settings
bzero(&newtio, sizeof(newtio)); // clear struct for new port settings
newtio.c_cflag = B57600 | 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] = 50;
newtio.c_cc[VMIN] = 0;
tcflush(sd, TCIFLUSH);
tcsetattr(sd, TCSANOW, &newtio);

And I am using this to read the port:

res = read(sd, inBuf, 3);
printf(“ser:%X %X %X : %d\n”, inBuf[0], inBuf[1],
inBuf[2], res);

It is all very straightforward, and I have no idea why this quit working.

Thanks for any help,

Mit

2

Have you checked this thread?
openqnx.com/PNphpBB2-viewtopic-t1003-.html

BTW, do a search on “devc-ser8250” on this site and see other discussions.

3

To answer my own question, I needed:

newtio.c_ispeed = B57600;
newtio.c_ospeed = B57600;

to set the speed correctly. I suppose Linux didn’t need / doesn’t have
those options.

Thanks…

Mit

4

Linux should have those members (it isn’t Posix if it doesn’t). Posix also says that one should not set these members directly, but should use the api calls cfsetispeed/cfsetospeed.

5

Yes, I realize Linux also has those members, but I didn’t need to set them
for my serial code to work?? Also, after I replied I did a little more reasearch into how to do this RIGHT, and found out about the setspeed commands. Hopefully I’m getting close to getting this working!

Thanks again,

Mit