gpio.hpp

C++ GPIO Pins Control Class

class BeagleBone::gpio: public BeagleBone::pin

This class provides an API for controlling GPIO pins.

To make the classes visible:

#include "bonelib/gpio.hpp"

static gpio* gpio::P8(unsigned char n)

Get the singleton instance that controls the GPIO function on pin #n on connector P8. This will automatically set the pin muxing to the GPIO functionality. Returns NULL if the pin does not offer a GPIO function.

static gpio* gpio::P9(unsigned char n)

Get the singleton instance that controls the GPIO function on pin #n on connector P9. This will automatically set the pin muxing to the GPIO functionality. Returns NULL if the pin does not offer a GPIO function.

int gpio::configure(pin::direction_t direction, pin::pulls_t pull = pin::NONE)

Configure the GPIO pin to the specified direction and pull resistors. The direction must be one of pin::IN or pin::OUT. The resistors must be one of pin::NONE, pin::PU or pin::PD.

pin::direction_t gpio::get_direction()

Return the current direction of the GPIO pin. The return value is one of pin::IN or pin::OUT.

pin::pulls_t gpio::get_pulls()

Return the current pull resistors on the pin. The return value is one of pin::NONE, pin::PU or pin::PD.

int gpio::set(unsigned char val)

Set the output value of the GPIO pin to the specified value (0 or 1). Return true it was succesful.

unsigned char gpio::get()

Return the current value of the GPIO pin. The value is one of 0 or 1.

Limitations

See the limitations for [pinmux.hpp].

Example

#include "bonelib/gpio.hpp"

BeagleBone::gpio* CS = BeagleBone::gpio::P8(2);
BeagleBone::gpio* DO = BeagleBone::gpio::P8(4);
BeagleBone::gpio* CLK = BeagleBone::gpio::P8(6);

CS->configure(BeagleBone::pin::OUT);
DO->configure(BeagleBone::pin::OUT);
CLK->configure(BeagleBone::pin::OUT);

CS->set(1);
for (int i = 0; i < 8; i++) {
   DO->set(txd & 0x01);
   CLK->set(1);
   CLK->set(0);
   txd >>= 1;
}
CS->set(0);