gpio.c File Reference

GPIO configuration and service functions. More...

#include <stdbool.h>
#include <stdint.h>
#include <avr/io.h>
#include <avr/wdt.h>
#include <util/delay.h>
#include "gpio.h"

Include dependency graph for gpio.c:

Functions
void	init_gpio_module (const struct gpio_mapping *const mappings, const uint8_t mappings_size)
void	configure_gpio_pin (const struct gpio_pin *const pin, const enum gpio_type type)
	Configures a GPIO pin. More...
bool	poll_gpio_input (const struct gpio_pin pin, const enum gpio_type type)
	Polls a GPIO input pin. More...
enum gpio_input_event	poll_gpio_input_timeout (const struct gpio_pin pin, const enum gpio_type type, uint8_t timeout)
	Polls a GPIO input pin with timeout. More...

Variables
const struct gpio	gpio
	A global structure with all available GPIO pins. More...

Detailed Description

GPIO configuration and service functions.

Function Documentation

configure_gpio_pin()

void configure_gpio_pin	(	const struct gpio_pin *	pin,
		enum gpio_type	type
	)

Configures a GPIO pin.

Parameters

pin	the GPIO pin to configure
type	the desired function / type of the pin

init_gpio_module()

void init_gpio_module	(	const struct gpio_mapping *const	mappings,
		const uint8_t	mappings_size
	)

poll_gpio_input()

bool poll_gpio_input	(	const struct gpio_pin	pin,
		enum gpio_type	type
	)

Polls a GPIO input pin.

Automatically de-bounces the pin if it is detected as active and returns as soon as the input returns to logical 0. Warning: Uses busy waiting!

Parameters

pin	the GPIO input pin to poll
type	the GPIO input type (pull-up or pull-down)

Returns

true if the input pin reads logical 1

See also

poll_gpio_input_timeout

poll_gpio_input_timeout()

enum gpio_input_event poll_gpio_input_timeout	(	const struct gpio_pin	pin,
		enum gpio_type	type,
		uint8_t	timeout
	)

Polls a GPIO input pin with timeout.

Reads and de-bounces an input pin and measures how long it is in logical high-state continuously. After a given amount of time the function announces the event by returning GPIO_INPUT_EVENT_LONG. If the input pin returns to low before the timeout was reached, GPIO_INPUT_EVENT_SHORT is returned. This function uses busy waiting, so all background tasks are stalled until the timeout is reached. When the timeout is set to zero, this function blocks until the input pin reads logical low again, which is what poll_gpio_input does.

Parameters

pin	the GPIO input pin to poll
type	the GPIO input type (pull-up or pull-down)
timeout	the timeout in [s/10], or 0 for infinity

Returns

the detected input event or GPIO_INPUT_EVENT_NONE

Variable Documentation

gpio

const struct gpio gpio

A global structure with all available GPIO pins.

This data structure provides a nice way to address GPIO pins. The pins are grouped into three headers with eight pins each and a group for the four solder jumpers - exactly representing the hardware interface. You can use these aliases to configure the pins you need and to get / set the state of the pin.

See also

configure_gpio_pin

init_gpio_module

gpio_get

gpio_set