Use the same pin to wake up and other uses

[clake]

Hi to all!

I'm trying to use the same GPIO to wake up the nrf52810 from system off and also use it to execute some functions. I have this code that is based on the example from this link: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.0.2/zephyr/samples/boards/nrf/system_off/README.html

// function to power off
static void power_off_system() {
	/* Configure to generate PORT event (wakeup) on button 1 press. */
	nrf_gpio_cfg_input(btn.pin, NRF_GPIO_PIN_PULLUP);
	nrf_gpio_cfg_sense_set(btn.pin, NRF_GPIO_PIN_SENSE_LOW);

	printk("Pwering off device\n");
	pm_state_force(0u, &(struct pm_state_info){PM_STATE_SOFT_OFF, 0, 0});

	/* Now we need to go sleep. This will let the idle thread runs and
	 * the pm subsystem will use the forced state. To confirm that the
	 * forced state is used, lets set the same timeout used previously.
	 */
	// k_sleep(2);
	k_msleep(2000);
}
/* Prevent deep sleep (system off) from being entered on long timeouts
 * or `K_FOREVER` due to the default residency policy.
 *
 * This has to be done before anything tries to sleep, which means
 * before the threading system starts up between PRE_KERNEL_2 and
 * POST_KERNEL.  Do it at the start of PRE_KERNEL_2.
 */
static int disable_ds_1(const struct device *dev)
{
	ARG_UNUSED(dev);

	pm_policy_state_lock_get(PM_STATE_SOFT_OFF);
	return 0;
}

SYS_INIT(disable_ds_1, PRE_KERNEL_2, 0);

This is executed when long press the button. Then in the wake up, it works but the button has some strange behavior like it us pulsed 2 times at the same time. The button is configured as an interrupt that enable a timer to test if is a long press or a simple press.

This is the configuration of the GPIO to use it as an interrupt:

gpio_init_callback(&button_cb_data, button_pressed, BIT(btn.pin));
gpio_add_callback(btn.port, &button_cb_data);

Also, there is a way to start the nrf with system off and wake it up with a long press?

Best regards

[Håkon Alseth]

Hi,

 

This is executed when long press the button. Then in the wake up, it works but the button has some strange behavior like it us pulsed 2 times at the same time.

Do you apply an external pull resistor on the pin? How is your debouncing implemented?

 

Kind regards,

Håkon

[clake]

Hi Hákon,

Is a software problem, I'm using the nrf52 DK with the board buttons. The problem is: If I configure one GPIO to use it as interrupt, then only with that I can't wake up the nrf from system_off. So, to be able to wake it up I have to configure the GPIO as sense to wake it up, but after configure as a sense then, when the nrf52 wake up from system off, the GPIO (I'm using the same as interrupt and for wake up) sense 2 time when I push the button. One quick fix that I've made was clean the configuration of the port when it wake up.

Is a more effective way to configure the same GPIO as an interrupt and to use it a sense to wake up?

Best regards

[Håkon Alseth]

Hi,

 

clake said:

after configure as a sense then, when the nrf52 wake up from system off, the GPIO (I'm using the same as interrupt and for wake up) sense 2 time when I push the button.

Systemoff means no clocks are running, only combinatory logic is available, such as a pin change or reset signal.

The wakeup condition is level triggered, meaning when that pin goes active; the nRF will reset and start up.

When waking up, if you get 2 interrupts on that pin, it actually means that you have gotten 3 events.

1 to initially wake up (where as the nRF starts from a reset state), and two afterwards.

 

What you need to do in order to avoid registering several events after boot-up is to handle this by debouncing the signal in software.

 

Kind regards,

Håkon 

[clake]

thanks for the reply!

And sorry for my late response. Can you please attach an example of how can I configure it using zephyr?

Best regards!

[Håkon Alseth]

Hi,

 

No, we do not have a specific sample that shows debouncing.

The gpio driver in zephyr does not have support for debouncing, but the DK buttons and LEDs library has:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/2.0.2/nrf/libraries/others/dk_buttons_and_leds.html

 

Kind regards,

Håkon

[clake]

Thanks for the reply

Best regards