Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

MAndris — Fri, 07 Mar 2025 08:44:34 GMT

Thank you

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

Marte Myrvold — Thu, 06 Mar 2025 12:57:41 GMT

Hi,

Great to hear that you figured it out!

[quote user="MAndris"]I believe these spikes occur because the device sends a data request every five seconds[/quote]

Yes, the device will send these data requests as part of the keep-alive mechanism.

[quote user="MAndris"]I disabled everything possible in the devicetree, but the power consumption did not decrease. What helped was adding the following lines to the config file:[/quote]

You should disable things both in devicetree and Kconfig to ensure that they are completely disabled and do not affect power consumption.

We also have the guide Power optimization recommendations, but it seems like you are already doing what is mentioned there.

Best regards,
Marte

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

MAndris — Wed, 05 Mar 2025 13:42:26 GMT

Thank you. I have achieved the desired result. The minimum power consumption in sleep mode is 4 µA, with periodic spikes. I believe these spikes occur because the device sends a data request every five seconds (as observed in the Zigbee sniffer, which shows data transmission).

I measured the average power consumption in sleep mode over five minutes, which turned out to be 13 µA. This is approximately four times more efficient than the MG22 from Silicon Labs.

I still don’t fully understand how exactly I achieved this result. I disabled everything possible in the devicetree, but the power consumption did not decrease. What helped was adding the following lines to the config file:

CONFIG_ADC=n
CONFIG_SERIAL=n
CONFIG_I2C=n
CONFIG_SPI=n

I haven't yet tested which specific setting had the most impact, but I am now confident that the product is more than competitive.

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

MAndris — Tue, 04 Mar 2025 15:37:43 GMT

Good afternoon, Marte. Thank you for your response.

In the Zigbee event handler, I log the number of each event that triggers it:

void zboss_signal_handler(zb_bufid_t bufid)
{
    zb_zdo_app_signal_hdr_t *sig_hndler = NULL;
    zb_zdo_app_signal_type_t sig = zb_get_app_signal(bufid, &sig_hndler);
    zb_ret_t status = ZB_GET_APP_SIGNAL_STATUS(bufid);
    LOG_INF("------zboss_signal_handler: signal = %u", sig);

And then, I process the event accordingly.

However, I am not currently reacting to the signal #define ZB_COMMON_SIGNAL_CAN_SLEEP 22U inside the handler, even though it appears frequently.

I assume that within this handler, I could implement the transition to sleep mode for the Zigbee device using zb_sleep_now();.

When the microcontroller starts up, I use the command:
zigbee_configure_sleepy_behavior(true);

I am not sure what exactly I changed, but power consumption has decreased 10 times and is now 370 μA. I really hope that this is not the limit.

Could the fact that I am using PWM on three pins for indication or other peripherals be affecting the power consumption?
Additionally, could there be extra power consumption due to the fact that I am measuring current on the development board, which might have some additional components drawing power?

Otherwise, the network connection is successful:

Joined network successfully (Extended PAN ID: 917b6a97525f25b3, PAN ID: 0xe3b1)
I: Network rejoin procedure stopped as NOT scheduled.
I: ------zboss_signal_handler: signal = 22
I: ------zboss_signal_handler: signal = 22

Best regards, Andris M.

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

Marte Myrvold — Tue, 04 Mar 2025 13:20:04 GMT

Hi,

[quote user=""]However, I did not see the microcontroller enter sleep mode at all. I even tried forcing it into sleep mode (zb_set_rx_on_when_idle(ZB_FALSE); zb_sleep_now();), but the microcontroller just reset with an error.[/quote]

Had the device joined a Zigbee network at this point? When you enable sleepy behavior with zigbee_configure_sleepy_behavior(true) or zb_set_rx_on_when_idle(ZB_FALSE), the device will enter sleep when there is nothing in the queue. This is done by the signal ZB_COMMON_SIGNAL_CAN_SLEEP being triggered. However, if the device has not joined a network, it will not go to sleep, as it will continue trying to join one.

[quote user=""]Is it possible to put the device into sleep mode when not in use in the Zigbee Light Switch example?[/quote]

You can enable sleepy behavior in the light switch sample by pressing button 2 while the device is booting. Make sure to do this when the device is booting before it has joined a network for the first time.

Best regards,
Marte

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

MAndris — Tue, 04 Mar 2025 13:18:31 GMT

Hello again,

I am continuing to explore this topic. Based on the power consumption table:
Power Consumption Table

The "POWER ON IDLE with GRTC 256 kB RAM (3 μA)" mode is acceptable for my power consumption requirements, but I do not yet understand how to achieve it. I am reading the available documentation, and I have two concepts in mind:

The system automatically reduces power consumption depending on the active resources, and I need to manually disable device drivers.
I manually issue a command to enter a low-power mode, with some function remaining active that can wake up the microcontroller from this state.

So far, deep sleep is the only mode I have successfully implemented. From the documentation, I understand that wake-up from this state can occur via a signal on GPIO pins (The DETECT signal generated by the GPIO peripheral).
PMU Documentation

This means I can implement my intended functionality using this mode. The key question is how long after pressing a button in sleep mode the microcontroller will reboot and send a Zigbee signal based on the pressed key. If this delay is too long, deep sleep mode may become impractical.

Currently, I am trying to write a simple example program to train myself in entering deep sleep and waking up via one of two buttons, using the nRF54L15 development board.

I have defined the button pins using DT aliases in the device tree and am using sw1 and sw2. I believe the microcontroller successfully enters sleep mode, but it does not wake up.

Current Code:

#include <zephyr/kernel.h>
#include <zephyr/sys/poweroff.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/logging/log.h>

LOG_MODULE_REGISTER(sleep_test, LOG_LEVEL_DBG);

#define WAKEUP_PIN1_NODE DT_ALIAS(sw1)
#define WAKEUP_PIN2_NODE DT_ALIAS(sw2)

void configure_wakeup_pins(void)
{
    LOG_INF("Configuring wakeup pins...");
    const struct device *gpio_dev1 = DEVICE_DT_GET(DT_GPIO_CTLR(WAKEUP_PIN1_NODE, gpios));
    const struct device *gpio_dev2 = DEVICE_DT_GET(DT_GPIO_CTLR(WAKEUP_PIN2_NODE, gpios));

    gpio_pin_configure(gpio_dev1, DT_GPIO_PIN(WAKEUP_PIN1_NODE, gpios), GPIO_INPUT | GPIO_PULL_UP);
    gpio_pin_configure(gpio_dev2, DT_GPIO_PIN(WAKEUP_PIN2_NODE, gpios), GPIO_INPUT | GPIO_PULL_UP);
    
    gpio_pin_interrupt_configure(gpio_dev1, DT_GPIO_PIN(WAKEUP_PIN1_NODE, gpios), GPIO_INT_EDGE_TO_ACTIVE);
    gpio_pin_interrupt_configure(gpio_dev2, DT_GPIO_PIN(WAKEUP_PIN2_NODE, gpios), GPIO_INT_EDGE_TO_ACTIVE);
    LOG_INF("Wakeup pins configured.");
}

int main(void)
{
        LOG_INF("Starting system...");
        configure_wakeup_pins();
        LOG_INF("Entering System OFF mode.");
        k_msleep(2000);
        sys_poweroff();
        LOG_ERR("This should never be printed! System OFF should not return.");
	while (1) {
		k_msleep(2000);
                LOG_INF("while 2000");
	}
}

Configuration File (`prj.conf`):

CONFIG_REBOOT=y
CONFIG_POWEROFF=y

CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_SERIAL=y
CONFIG_GPIO=y
CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y
CONFIG_LOG=y

Additionally, I would also like to implement "POWER ON IDLE with GRTC" mode in the future to better understand power management in Zephyr and the nRF54L15.

I would appreciate any references to articles or documentation that can help me better understand power management modes and their proper implementation.

Thank you in advance!

Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

RE: Help with Sleep Mode on nRF54L15 in Zigbee Light Switch

Current Code:

Configuration File (prj.conf):

Configuration File (`prj.conf`):