Button Handler

Buttons handling module. More...

Data Structures
struct	app_button_cfg_t
	Button configuration structure. More...
struct	pin_transition_t
	Pin transition direction struct. More...

Macros
#define	APP_BUTTON_PUSH   1
#define	APP_BUTTON_RELEASE   0
#define	APP_BUTTON_ACTIVE_HIGH   1
#define	APP_BUTTON_ACTIVE_LOW   0

Typedefs
typedef void(*	app_button_handler_t )(uint8_t pin_no, uint8_t button_action)
	Button event handler type.

Functions
uint32_t	app_button_init (app_button_cfg_t *p_buttons, uint8_t button_count, uint32_t detection_delay)
	Function for initializing the Buttons. More...
uint32_t	app_button_enable (void)
	Function for enabling button detection. More...
uint32_t	app_button_disable (void)
	Function for disabling button detection. More...
uint32_t	app_button_is_pushed (uint8_t button_id, bool *p_is_pushed)
	Function for checking if a button is currently being pushed. More...

Detailed Description

Buttons handling module.

The button handler uses the GPIOTE Handler to detect that a button has been pushed. To handle debouncing, it will start a timer in the GPIOTE event handler. The button will only be reported as pushed if the corresponding pin is still active when the timer expires. If there is a new GPIOTE event while the timer is running, the timer is restarted.

Note

The app_button module uses the app_timer module. The user must ensure that the queue in app_timer is large enough to hold the app_timer_stop() / app_timer_start() operations which will be executed on each event from GPIOTE module (2 operations), as well as other app_timer operations queued simultaneously in the application.

Even if the scheduler is not used, app_button.h will include app_scheduler.h, so when compiling, app_scheduler.h must be available in one of the compiler include paths.

Macro Definition Documentation

#define APP_BUTTON_ACTIVE_HIGH   1

Indicates that a button is active high.

#define APP_BUTTON_ACTIVE_LOW   0

Indicates that a button is active low.

#define APP_BUTTON_PUSH   1

Indicates that a button is pushed.

#define APP_BUTTON_RELEASE   0

Indicates that a button is released.

Function Documentation

uint32_t app_button_disable

(

void

)

Function for disabling button detection.

Return values

NRF_ERROR_INVALID_PARAM	GPIOTE has to many users.
NRF_ERROR_INVALID_STATE	Button or GPIOTE not initialized.
NRF_SUCCESS	Button detection successfully enabled.

uint32_t app_button_enable

(

void

)

Function for enabling button detection.

Return values

NRF_ERROR_INVALID_PARAM	GPIOTE has to many users.
NRF_ERROR_INVALID_STATE	Button or GPIOTE not initialized.
NRF_SUCCESS	Button detection successfully enabled.

uint32_t app_button_init	(	app_button_cfg_t *	p_buttons,
		uint8_t	button_count,
		uint32_t	detection_delay
	)

Function for initializing the Buttons.

This function will initialize the specified pins as buttons, and configure the Button Handler module as a GPIOTE user (but it will not enable button detection).

Note

Normally initialization should be done using the APP_BUTTON_INIT() macro

app_button_enable() function must be called in order to enable the button detection.

Parameters

[in]	p_buttons	Array of buttons to be used (NOTE: Must be static!).
[in]	button_count	Number of buttons.
[in]	detection_delay	Delay from a GPIOTE event until a button is reported as pushed.

Returns

NRF_SUCCESS on success, otherwise an error code.

uint32_t app_button_is_pushed	(	uint8_t	button_id,
		bool *	p_is_pushed
	)

Function for checking if a button is currently being pushed.

Parameters

[in]	button_id	Button index (in the app_button_cfg_t array given to app_button_init) to be checked.
[out]	p_is_pushed	Button state.

Return values

NRF_SUCCESS	State successfully read.
NRF_ERROR_INVALID_PARAM	Invalid button index.