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I try to use pio button. Typing cat /dev/button I can see that the button drivers are working. How can I use the functions in altera_pio_button.c to make my own uClinux app? thanks stepa
I think the following code works... it's been awhile since I looked at it. I think there may have been an issue with shutting down the app properly but it should give you some good ideas as to how to proceed.
#include <stdio.h># include <unistd.h># include <fcntl.h># include <stdlib.h>
/* open /dev/button device for blocked reading
* whenever button is pressed,
* display number of times button was pressed since startup
*/
int
main (int argc, char* argv)
{
int fd;
char path = "/dev/button";
int numclicks = 0;
char buf;
fd = open (path, O_RDONLY);
if (fd < 0) {
/* error occurred */
perror ("open");
exit (EXIT_FAILURE);
} else {
printf ("opened %s\n", path);
}
/* file is now open for reading... do your stuff... */
while (read (fd, buf, 1) != 0) {
if (buf == '1') {
numclicks += 1;
}
printf ("The button has been pushed %d times.\n", numclicks);
}
if (close (fd) < 0) {
perror ("close");
exit (EXIT_FAILURE);
} else {
printf ("closed %s\n", path);
}
exit (EXIT_SUCCESS);
}
