Ktam3874/pitx software guide – Kontron KTAM3874-pITX User Manual
Page 69
KTD-S0057-I
Page 65 Linux® Programming Examples (DebianTM)
KTAM3874/pITX Software Guide
void gpio_close_read (int gpio_pin)
{
close (fd [gpio_pin]);
}
int main (void)
{
int i, value;
printf ("\nGPIO test program\n");
if ((! gpio_export (GP2_17)) && (! gpio_set_direction (GP2_17, GPIO_OUT)))
{
if (! gpio_open_write (GP2_17))
{
for (i = 0; i < MAX_CNT; i++)
{
gpio_write
(GP2_17,
1);
usleep
(SLP_TIME);
gpio_write
(GP2_17,
0);
usleep
(SLP_TIME);
}
gpio_close_write
(GP2_17);
}
else
{
printf ("\nCannot open GPIO !\n");
gpio_unexport
(GP2_17);
return
-1;
}
gpio_unexport
(GP2_17);
}
else
{
printf ("\nGPIO init error !\n");
gpio_unexport
(GP2_17);
return
-1;
}
printf ("GPIO output part successfully finished. Please press Enter.");
getchar
();
if ((! gpio_export (GP2_17)) && (! gpio_set_direction (GP2_17, GPIO_IN)))
{
if (! gpio_open_read (GP2_17))
{
if (! gpio_read (GP2_17, &value))
printf ("Input value on GP2[17] is %d\n", value);
gpio_close_read
(GP2_17);
}