GPIO_GetValue Function
Header: #include <applibs/gpio.h>
Gets the current value of a GPIO.
GPIO functions are thread-safe between calls to different GPIOs; however, it is the caller’s responsibility to ensure thread safety for accesses to the same GPIO.
int GPIO_GetValue(int gpioFd, GPIO_Value_Type *outValue);
Parameters
gpioFd
The file descriptor for the GPIO.outValue
The GPIO_Value read from the GPIO - GPIO_Value_High or GPIO_Value_Low.
Errors
Returns -1 if an error is encountered and sets errno
to the error value.
EFAULT: the
outValue
is NULL.EBADF: the
gpioFd
is not valid.
Any other errno
may also be specified; such errors aren't deterministic and the same behavior might not be retained through system updates.
Return value
Returns 0 for success, or -1 for failure, in which case errno
will be set to the error value.
Application manifest requirements
To access individual GPIOs, your application must identify them in the Gpio field of the application manifest.