GPIO

Functions to communicate with equipments using GPIO. More...

Functions
int	eris_get_list_of_gpio (char *buffer, size_t size)
	Get a list of available GPIOs.
int	eris_request_gpio_for_input (const char *id)
	Reserve a GPIO and configure it for input.
int	eris_request_gpio_for_output (const char *id, int value)
	Configure a GPIO for output and set its initial value.
int	eris_release_gpio (const char *id)
	Release a GPIO that you don't use anymore.
int	eris_read_gpio_value (const char *id)
	Read the value on a GPIO configured in input.
int	eris_write_gpio_value (const char *id, int value)
	Write a value on a GPIO configured in output.

Detailed Description

Functions to communicate with equipments using GPIO.

Function Documentation

eris_get_list_of_gpio()

int eris_get_list_of_gpio	(	char *	buffer,
		size_t	size )

Get a list of available GPIOs.

Parameters

buffer	The buffer to fill with the list.
size	The size of the buffer.

Returns

0 on success, -1 on error and errno is set appropriately.

This function fills the provided buffer with a JSON array of items:

[ {
      "id": "gpiochip0:17",
      "name": "BUTTON_1"
  }
]

eris_read_gpio_value()

int eris_read_gpio_value

(

const char *

id

)

Read the value on a GPIO configured in input.

Parameters

id	The id of the GPIO.

Returns

On success this function return 0 or 1 depending on the GPIO input. On error -1 is returned and errno is set appropriately.

eris_release_gpio()

int eris_release_gpio

(

const char *

id

)

Release a GPIO that you don't use anymore.

Parameters

id	The id of the GPIO.

Returns

0 on success, -1 on error and errno is set appropriately.

eris_request_gpio_for_input()

int eris_request_gpio_for_input

(

const char *

id

)

Reserve a GPIO and configure it for input.

Parameters

id	The id of the GPIO.

Returns

0 on success, -1 on error and errno is set appropriately.

id is the string contained in the id field of a GPIO object returned by eris_get_list_of_gpio().

eris_request_gpio_for_output()

int eris_request_gpio_for_output	(	const char *	id,
		int	value )

Configure a GPIO for output and set its initial value.

Parameters

id	The name of the GPIO.
value	The new value for the GPIO.

Returns

0 on success, -1 on error and errno is set appropriately.

`id` is the string contained in the id field of a GPIO object returned by eris_get_list_of_gpio().

eris_write_gpio_value()

int eris_write_gpio_value	(	const char *	id,
		int	value )

Write a value on a GPIO configured in output.

Parameters

id	The id of the GPIO.
value	The value (0 or 1) to write to the GPIO.

Returns

0 on success, -1 on error and errno is set appropriately.