The GPIOTE Handler was triggered several times (SD14, 52840)

[mjt110]

Hi, I was confused about the behavior of GPIOTE Handler  module。I defined a handler(gpiote_event_handler) and I hope when the GPIO Pin(0.14) is changed from high to low or low to high, this handler could be triggered. When I reversed the state of Pin(0.14) just one time, my handler was triggered several times.

My code:

static app_gpiote_user_id_t   m_gpiote_user_id;
static uint32_t  p014_bitmask = 0x00004000; 

static void gpiote_event_handler(uint32_t const * p_event_pins_low_to_high, uint32_t const * p_event_pins_high_to_low){
	if(*p_event_pins_low_to_high & p014_bitmask){
		NRF_LOG_INFO("gpiote_event_handler p014 low_to_high");
	}else if(*p_event_pins_high_to_low & p014_bitmask){
		NRF_LOG_INFO("gpiote_event_handler p014 high_to_low");
	}
}

void init(void){
	APP_GPIOTE_INIT(3);
	
	nrf_gpio_cfg_input(NRF_GPIO_PIN_MAP(0,14), NRF_GPIO_PIN_PULLDOWN);
	
	uint32_t err_code;
	err_code = app_gpiote_user_register(&m_gpiote_user_id, &p014_bitmask, &p014_bitmask, gpiote_event_handler);
	APP_ERROR_CHECK(err_code);
	
	err_code = app_gpiote_user_enable(m_gpiote_user_id);
	APP_ERROR_CHECK(err_code);
}

and the result:

I hope my handler could be triggered just one time when the P(0.14) pin is set from low to high，and just one time when the P(0.14) pin is clear from high to low.

Is that possible?

[Einar Thorsrud]

Hi,

I assume the input here is connected to a button/switch or similar? If so, it will typically be noisy ("bounce"), and therefore you will get multiple events if you don't have a low pass filter on the input. If it is, the best is if you can fix it in HW. Alternatively you have to do debouncing in SW, for instance using the Button handling library.

[mjt110]

Hi  Einar, thanks for your reply! The input is connected to a button。Sometimes I did not push the button and the handler had already been triggered several times, is that normal?

Kind regards.

[Einar Thorsrud]

Yes, then this is caused by noise from the button, which is normal. You need to handle it in some way, either with a RC filter in HW or by debouncing in software, as suggested in my previous reply.

[mjt110]

That explains a lot，thank you so much！