about GPIOTE event

[Hansome]

I'm developing a fingerprint-related project.
When the finger touches, the fingerprint sensor generates a pulse signal.
NRF52810 will triggers a GPIOTE callback, then wakeup and start BLE advertisement.

When finger touches, the problem is,
a. The oscilloscope always can display the pulse waveforms
b. But the GPIOTE callback has the probability of being locked up
c. Once locked up, the GPIOTE callback event never happen again, until reset

A lot of testing work shows that, this problem is easy to occur when UART/UARTE is used.

What I want to ask is, how to configure it to ensure that GPIOTE event will happen? Thanks!

[ovrebekk]

Hi

Can you show me the code you use to initialize the GPIOTE callback?

Is this the only pin using GPIOTE, or do you have other pins connected to the GPIOTE, such as buttons?

Best regards
Torbjørn

[Hansome]

Only one pin using GPIOTE,

static void _wakeup_pin_handler(nrf_drv_gpiote_pin_t pin, nrf_gpiote_polarity_t action)
{

	_pin_flag = true;
	
}

	
void init(void)
{
	
	nrf_drv_gpiote_in_config_t cfg = GPIOTE_CONFIG_IN_SENSE_HITOLO(false);
	
	nrf_drv_gpiote_init();
	cfg.pull = NRF_GPIO_PIN_PULLUP;
	nrf_drv_gpiote_in_init(_WAKEUP_PIN, &cfg, _wakeup_pin_handler);
	nrf_drv_gpiote_in_event_enable(_WAKEUP_PIN, true);

}	
	

void proc(void)
{

	if(_pin_flag){
		wakeup();
		_pin_flag = false;
	}
	
}

[ovrebekk]

Hi 

You should be able to set the GPIOTE interrupt priority by changing the GPIOTE_CONFIG_IRQ_PRIORITY define in sdk_config.h. By default it is set to 6, which is the same as the UART interrupt priority.

Maybe you can try setting it to 2 or 3 and see if it works better?

Best regards
Torbjørn

[Hansome]

Setting GPIOTE_CONFIG_IRQ_PRIORITY = 2 will affect the softdevice?

[ovrebekk]

Hi 

No, priorities 2, 3, 6, and 7 are available when using the SoftDevice. 

Best regards
Torbjørn

[Hansome]

So as shown in the figure, I'm a little confused,

[ovrebekk]

Hi 

If you want to call a SoftDevice function (any function with the sd_ prefix), or an SDK function that calls into the SoftDevice under the hood, you have to be in interrupt priorty 6, 7, or in thread context. 

The GPIOTE driver should not need to call any SoftDevice functions, so it should be safe to run at interrupt priorities 2 and 3 also. 

Best regards
Torbjørn

[Hansome]

Thanks!