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Altera_Forum's avatar
Altera_Forum
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15 years ago

Error while trying to use RS232 port on DE2 2c35 running uClinux

Hi all, I try to use RS232 port on my DE2 board to communicate with my device (magnetic card reader). But when I try to use the command "cat test.txt > /dev/ttyS0", the console appears with "/de...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

thanks for replying Mr actris, I have solved that problem by updating to nios2-linux 2009 version. I can open and write data to "dev/ttyS0" well.

But I encounter another problem now. I can't read from "dev/ttyS0" by using read or fread functions. :(

here's my code: 


# include <string.h>
# include <unistd.h>  
# include <fcntl.h>   
# include <errno.h>   
# include <termios.h> 
int main(void)
{
	char buf;	
	int fd1, fd2, count;
	
 	fd1 = open("/dev/ttyS0", O_RDWR | O_NOCTTY | O_NDELAY);
	fd2 = open("/mnt/SD/t.txt",O_WRONLY);
      	if (fd1 == -1)
      	{
       		perror("open_port: Unable to open /dev/ttyS0 - ");
	}
      	
	while(count = read(fd1, buf, 10) > 0)
		write(fd2, buf, 10);
	
	close(fd1);
	close(fd2);
      //return (fd);
}