ABOUT ZIGBEE OF NRF54L15

[jermi]

Hi Nordic：

    We are currently testing Zigbee on the nRF54L15 platform using the Zigbee R23-add-on-V1.0.0 SDK. It has been observed that when a low-power node disconnects from the gateway, it cannot enter low-power mode until it successfully rejoins the network. Are there any solutions to address this issue?

Regard Best

Jermi

[Edvin]

Hello,

Sorry for the late reply, Jermi. We are a bit short staffed due to summer holidays here in Norway.

What you are seeing is probably that when the node is no longer part of the network, it tries to rejoin the network, and hence, the radio is being used a lot more than when it is in the low power state. 

How do you want the device to behave? Do you want it to remain shut down the radio when it leaves? One possibility would be to start the rejoin process on a button press, perhaps? Or perhaps you can have it try to rejoin immediately, but only for a few minutes? I believe this is actually what it is doing, but I don't know how long you observed the device after it lost the network. 

Best regards,

Edvin

[sg3]

Hi, Edvin:

We hope that after the rejoin process is completed, even if it is not successful, the child device can still enter the low-power mode normally.

[Edvin]

Yes. That is the expected behavior. After it either successfully joins a network, or the join attempt times out, the radio should be powered off, and it should enter a low power state. What is it that you are observing? Have you tried measuring the current consumption using a PPK2 board?

Best regards,

Edvin

[sg3]

The phenomenon I observed is that the device did not enter a low-power state during the interval between two rejoins. Moreover, even after the rejoin process ended (approximately 15 minutes later), the device still did not enter a low-power state, and there was a continuous current of 3.8 mA.

[Edvin]

Hello,

Is this with one of our samples or your own application? If so, have you tried to measure on e.g. the light_switch sample? Is it similar?

Best regards,

Edvin

[sg3]

Yes, only a few modifications were made to the light switch example.If possible, could you help test the power consumption using the official development board?3487.light_switch.zip

[Edvin]

This is what I see using the unmodified light_switch sample:

The chunk in the middle is when I removed the coordinator, and when I powered it back on, it went down to normal current consumption (which is a bit high in this case, but logging was turned on, keeping the HFCLK running at all times).

I will test your application tomorrow (I spent a bit too long getting the Zigbee addon up and running, so didn't have time for it today)

Best regards,

Edvin

[Edvin]

Your application also goes down after it rejoins the network:

You can see that I disconnected the coordinator in the middle, but then turned it back on. In the marked section (the greyed out) you can see that it goes back into low power mode, with an average of 392µA (I turned on UART logging, so it will be lower if this is disabled).

What are you using to measure the current consumption? And what does it look like before you disconnect it from the network? What is the current consumption then?

Best regards,

Edvin

[sg3]

We use Otii to measure the device’s power consumption.

Before disconnect, the device can enter low-power mode, consuming around 3-4uA. However, if the rejoin fails or the gateway is never powered on, the device will never enter low-power mode (I tested for about 30 minutes), and it will continuously consume 3.8mA.