Thread: Moxa 7112 Programming

> portno = 0x98200000; // Use ttyS0
> ioperm(portno, 1, 1); // Allow read and write access
How about using open / read / write / close / ioctl ?
In other words, the standard API for accessing devices.

You're making vast assumptions that your h/w architecture resembles an x86 PC.

Forget anything you ever read about programming ports if you learnt it from looking at DOS code.

How come your 5 lines grew to a 9KB file?

Create a simple test program which just outputs a short message, and get that working first.

Ok, sorry was rushing to get out of work so just put the entire program on here! Here's a shortened version with just the output code.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <asm/io.h>
#include <moxadevice.h>
#include <termios.h>
#include <fcntl.h>
#include <errno.h>

int n, fd;

int open_port(fd)
{
	fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
	if (fd < 0)
	{
		perror("open_port: /dev/ttyS0 - ");
	}
	else
	{
		fcntl(fd, F_SETFL, 0);
	}
	return (fd);
}


int main(int argc, char* argv[])

{
        open_port();
	n = write(fd, "test", 4);	     // Output the data to fd for the length of the string
	if (n < 0)
	{
		printf("Write failed!");
	}	
	return(0);
}

Ok I think that's it... It compiles ok but I don't get output or any error messages. I'm not sure if I need to set the options for the port, if I just leave it like I did will it just output as default? eg 19200kbs, no flow control...

Thanks

Ok I think I messed up the function call in that, so I messed around and have tried it this way, also with no luck. It outputs "35", which I guess means it opened the port ok and sent 5 characters to the port?

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <asm/io.h>
#include <moxadevice.h>
#include <termios.h>
#include <fcntl.h>
#include <errno.h>

int n, fd;
char jazz[5];

int main()
{
	fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
	printf("&#37;d", fd);
	if (fd < 0)
	{
		perror("open_port: /dev/ttyS0 - ");
	}
	else
	{
		fcntl(fd, F_SETFL, 0);
	}
	strcpy(jazz, "test");
	n = write(fd, &jazz, sizeof(jazz));
	printf("%d", n);
	if (n < 0)
	{
		printf("Write failed!");
	}	
	return(0);
}

Thanks

> n = write(fd, &jazz, sizeof(jazz));
Drop the &

strlen would have been better, then you don't send a \0 (maybe that doesn't matter).

> It outputs "35", which I guess means it opened the port ok and sent 5 characters to the port?
Yep, sounds good.

> I'm not sure if I need to set the options for the port, if I just leave it like I did will it just output as default? eg 19200kbs, no flow control...
I've no idea what the default port config on your machine is.
Try an ioctl() call to get the current config, and print it out.

It's definitely worth messing with the port config at the other end (different baud rates etc) to see if anything at all is being sent.

Another thing, you could close the port explicitly.