ADLINK Technology cRTV-24, User Manual

Page: 173 / 178

Programming Guide 163
Proprietary properties
Except standard APIs, we also provide a proprietary IO control
which can read and write external general purpose IO pin.
/* configure the direction (in or out) of each
gpio bit prior to reading or writing gpio.
*/
int config_gpio (void)
{
unsigned int value = 0xC3FEFF;
if (-1 == ioctl (fd,
BT878_S_GPIO_OUT_ENABLE, &value))
return -1;
return 0;
}
int read_gpio (void)
{
unsigned int value;
if (-1 == ioctl (fd, BT878_G_GPIO_VALUE,
&value))
return -1;
value &= 0x100;// bit 8 is used to store the
input value
if(value)
return 1;
else
return 0;
}
int write_gpio (int value)
{
unsigned int gpio;
if (-1 == ioctl (fd, BT878_G_GPIO_VALUE,
&gpio))
return -1;
gpio |= 0x40;// bit 6 is used to set the
output
if(value)
gpio -= 0x40;
if (-1 == ioctl (fd, BT878_S_GPIO_VALUE,
&gpio))
return -1;
return 0;
}