[nRF54L15 DK][Zephyr] How to implement deep sleep + interrupt-driven wakeup?

[pv7vishnu]

Hello,

I am exploring power management on the nRF54L15 DK with nRF Connect SDK v2.8.0 (Zephyr v3.7.99).

My goal is to:

• Enter deep sleep / system off mode.

• Wake up on an external GPIO interrupt ( Interrupt from LSM6DSL IMU Sensor).

What I tried so far

• Tested with LSM6DSL IMU interrupt connected to the DK.

  • When the system is running normally (no sleep), the LSM6DSL interrupt is firing correctly.

  • But when entering system off / sleep, the interrupt does not wake the device.

  • Tried with k_sleep(K_FOREVER) and sys_poweroff(). for both interrupt is not waking up the device
    
    

• Tested the system off demo sample (as-is from the SDK).

  • It enters system off successfully.

  • However, wakeup from Button0 (sw0) did not work on the nRF54L15 DK.

• Tried adding wakeup-source; property in a device tree overlay:
  
  / {
  button0 {
  wakeup-source;
  };
  };

   Still no wakeup on button press.

  Environment

  • Board: nRF54L15 DK
  • NCS: v2.8.0
  • Toolchain: VS Code + west build

  Questions

  • What is the recommended way to implement deep sleep with interrupt-driven wakeup on nRF54L15?
  • Are there additional device tree settings or GPIOTE configurations required beyond wakeup-source;?
  • Does GPIO wakeup from sleep / system off currently work on nRF54L15 DK, or is this feature still pending support?
  • Are there reference examples or low power samples for nRF54l15 showing interrupt-driven wakeup?

  

  • lsm6dsl interrupt configure code snippet

  int configure_lsm6dsl_interrupt(void)

  {

      int rc;

      LOG_INF("Configuring LSM6DSL GPIO interrupt...");

  
  

      if (!device_is_ready(int_gpio.port)) {

          LOG_ERR("GPIO device not ready");

          return -ENODEV;

      }

  
  

      LOG_INF("GPIO device ready, configuring pin gpio %s, %d as input", int_gpio.port->name, int_gpio.pin);

      rc = gpio_pin_configure_dt(&int_gpio, GPIO_INPUT); // GPIO_PULL_DOWN

      if (rc) {

          LOG_ERR("Failed to configure GPIO pin %d: %d", int_gpio.pin, rc);

          return rc;

      }

  
  

      LOG_INF("Initializing GPIO callback structure...");

      //gpio_init_callback(&lsm_int_cb, lsm6dsl_no_motion_isr, 1U << int_gpio.pin);

      gpio_init_callback(&lsm_int_cb, lsm6dsl_no_motion_isr, BIT(int_gpio.pin));

  
  

      LOG_INF("Adding GPIO callback to port...");

      rc = gpio_add_callback(int_gpio.port, &lsm_int_cb);

      if (rc) {

          LOG_ERR("Failed to add GPIO callback: %d", rc);

          return rc;

      }

  
  

      LOG_INF("Enabling edge interrupt on GPIO pin...");

      rc = gpio_pin_interrupt_configure_dt(&int_gpio, GPIO_INT_LEVEL_HIGH | GPIO_INT_WAKEUP); //GPIO_INT_EDGE_TO_ACTIVE //GPIO_INT_LEVEL_ACTIVE //GPIO_INT_LEVEL_HIGH

      if (rc) {

          LOG_ERR("Failed to configure GPIO interrupt: %d", rc);

          return rc;

      }

  
  

      LOG_INF("LSM6DSL GPIO interrupt configured successfully on pin %d", int_gpio.pin);

  
  

      uint32_t abs_pin = NRF_DT_GPIOS_TO_PSEL(DT_NODELABEL(lsm6dsl), irq_gpios);

      uint32_t sense = nrf_gpio_pin_sense_get(abs_pin);

      printk("Pin %d sense setting: %d\n", abs_pin, sense);

      printk("  NRF_GPIO_PIN_NOSENSE   = %d\n", NRF_GPIO_PIN_NOSENSE);

      printk("  NRF_GPIO_PIN_SENSE_LOW = %d\n", NRF_GPIO_PIN_SENSE_LOW);

      printk("  NRF_GPIO_PIN_SENSE_HIGH= %d\n", NRF_GPIO_PIN_SENSE_HIGH);

  
  

      return 0;

  }

[Elfving]

Hi Vishnu,

When it comes to power off, I believe that might be a bit different on the 54L15. We have a bit about that here, and here for instance, though this quick sample mentioned by a colleague of mine might be more helpful. 

And regarding having a pin wake-up, have a look at this other quick example I made for a customer earlier, that I think should also work for the nRF54L15 as well. You might have to add target_include_directories(app PRIVATE hal) to cmakelists to run it.

#include <stdio.h>
#include <zephyr/kernel.h>
#include <zephyr/drivers/gpio.h>


#include <hal/nrf_gpio.h>
#include <hal/nrf_power.h>
#include <hal/nrf_regulators.h>

/* 1000 msec = 1 sec */
#define SLEEP_TIME_MS   1000

/* The devicetree node identifier for the "led0" alias. */
#define LED0_NODE DT_ALIAS(led0)

/* The devicetree node identifier for the "sw0" alias (button0). */
#define SW0_NODE DT_ALIAS(sw0)

/*
 * A build error on this line means your board is unsupported.
 * See the sample documentation for information on how to fix this.
 */
static const struct gpio_dt_spec led = GPIO_DT_SPEC_GET(LED0_NODE, gpios);
static const struct gpio_dt_spec button = GPIO_DT_SPEC_GET(SW0_NODE, gpios);

int main(void)
{
	int ret;
	int iterate=0;
	int naptime = 6;
	bool led_state = true;
	printk("Count down to System OFF mode: T-%d blinks\n", naptime/2);

	if (!gpio_is_ready_dt(&led)) {
		return 0;
	}

	if (!gpio_is_ready_dt(&button)) {
		printk("Error: button device %s is not ready\n", button.port->name);
		return 0;
	}

	ret = gpio_pin_configure_dt(&led, GPIO_OUTPUT_ACTIVE);
	if (ret < 0) {
		return 0;
	}

	ret = gpio_pin_configure_dt(&button, GPIO_INPUT);
	if (ret < 0) {
		printk("Error %d: failed to configure %s pin %d\n",
		       ret, button.port->name, button.pin);
		return 0;
	}

	/* Configure the button pin for wake-up on low signal (button press) */
	nrf_gpio_cfg_sense_set(button.pin, NRF_GPIO_PIN_SENSE_LOW);

	while (iterate < naptime) {
		ret = gpio_pin_toggle_dt(&led);
		if (ret < 0) {
			return 0;
		}
		iterate++;

		led_state = !led_state;
		printf("LED state: %s\n", led_state ? "ON" : "OFF");
		k_msleep(SLEEP_TIME_MS);
	}

	printk("Entering sleep mode...\n");
	/* Enter sleep mode */
	nrf_regulators_system_off(NRF_REGULATORS);

	return 0;
}

wakeup-source

I am not that familiar with the wakeup-source property, but I do not think it does much by itself.

Regards,

Elfving