gpio.h File Reference

Interface to the GPIO peripheral. More...

#include <stdint.h>

Go to the source code of this file.

Macros
#define	BCM_MIN   0
	The lowest valid bcm port number.
#define	BCM_MAX   27
	The highest valid bcm port number.
#define	PORT_FUNCTION_INPUT   0
	Port function: Input. used in gpio_setFunction()
#define	PORT_FUNCTION_OUTPUT   1
	Port function: Output. used in gpio_setFunction()
#define	PORT_FUNCTION_ALT_0   4
	Port function: Alternative function 0. used in gpio_setFunction()
#define	PORT_FUNCTION_ALT_1   5
	Port function: Alternative function 1. used in gpio_setFunction()
#define	PORT_FUNCTION_ALT_2   6
	Port function: Alternative function 2. used in gpio_setFunction()
#define	PORT_FUNCTION_ALT_3   7
	Port function: Alternative function 3. used in gpio_setFunction()
#define	PORT_FUNCTION_ALT_4   3
	Port function: Alternative function 4. used in gpio_setFunction()
#define	PORT_FUNCTION_ALT_5   2
	Port function: Alternative function 5. used in gpio_setFunction()

Functions
int	gpio_init ()
	Initializes the interface, to be called before any other function in this file. More...
int	gpio_isInit ()
	true if gpio_init has been called with success
int	gpio_setFunction (int bcmPort, int function)
	Sets the function of the specified port. More...
int	gpio_setOutput (int bcmPort, int value)
	Sets the output at the specified port. The port will output this value if set to the output function. If you use this function with the port not set to output then the port will remember the value until you set it to the output function. More...
int	gpio_setOutputAll (uint64_t set, uint64_t clear)
	sets all the specified gpios to the specified values More...

Detailed Description

Interface to the GPIO peripheral.

This peripheral is able to set the function of each GPIO port and it's output status.
See documentation at "BCM2835 ARM peripherals" page 89

Function Documentation

int gpio_init

(

)

Initializes the interface, to be called before any other function in this file.

Returns

negative in case of error

int gpio_setFunction	(	int	bcmPort,
		int	function
	)

Sets the function of the specified port.

Parameters

bcmPort	The port bcm number
function	The desired function (PORT_FUNCTION_INPUT, PORT_FUNCTION_OUTPUT, PORT_FUNCTION_ALT_x)

Returns

negative in case of error

int gpio_setOutput	(	int	bcmPort,
		int	value
	)

Sets the output at the specified port. The port will output this value if set to the output function. If you use this function with the port not set to output then the port will remember the value until you set it to the output function.

Parameters

bcmPort	The port bcm number
value	0 means low, any other number means high

Returns

negative in case of error

int gpio_setOutputAll	(	uint64_t	set,
		uint64_t	clear
	)

sets all the specified gpios to the specified values

Parameters

set	The gpios to set to 1
clear	The values to set to 0

Returns

negative in case of error