nRF7002 - wlan0 interface goes down after repeated making HTTP requests

RE: nRF7002 - wlan0 interface goes down after repeated making HTTP requests

tomtran_montage — Wed, 09 Jul 2025 17:38:47 GMT

Thanks for the feedback. Yeah, this doesn't even have the MQTT library that I want to include. Hmm, this is a custom board with the nRF52840+nRF7002 on it. Getting it to even started working was a challenge in itself. I did notice that it's experimental. I am talking to management about switching to the nRF5340 now.

RE: nRF7002 - wlan0 interface goes down after repeated making HTTP requests

Elfving — Wed, 09 Jul 2025 08:19:22 GMT

[quote user="tomtran_montage"]Building the WIFI application is challenging because the nRF52840 has only 256KB RAM, which built with NCS v3.0.1 reaches RAM maximum. Tweaking stack sizes (prj.conf) to fit the app+zephyr OS into 256KB could possibly have ramifications to the system driver stack etc.[/quote]

Yeah, that is a tough one. The memory requirements for our Wi-Fi stack is already a bit high no matter what nRF you use, so using the NRF52840 instead of a 53 can make this particularly difficult. Note that support for the nRF52840 is currently listed as experimental here. So it is expected to work, though we haven't taken it through any rigorous testing.

I believe I've also seen crashes like this due to memory exhaustion. It might be that some extra ram rummaging would have better ramifications, and I can also ask the relevant R&D team if they have any ideas on this. But before we get to that, is switching to the nRF5340 an option for you?

Regards,

Elfving

RE: nRF7002 - wlan0 interface goes down after repeated making HTTP requests

tomtran_montage — Mon, 07 Jul 2025 17:08:16 GMT

My host MPU is a nRF52840 controlling a nRF7002. Building the WIFI application is challenging because the nRF52840 has only 256KB RAM, which built with NCS v3.0.1 reaches RAM maximum. Tweaking stack sizes (prj.conf) to fit the app+zephyr OS into 256KB could possibly have ramifications to the system driver stack etc.

I tried with both NCS version v2.9.1 and v3.0.1. Only that v3.0.1 last a few minutes longer before it crashes. The snapshot below is from v3.0.1

I guess my question would be why is the interface going down? A few questions comes to mind:

Is it entering low-power mode?
Why would the WIFI interface which is currently active decides to go down?
Is nRF7002 low-power mode periodic?

I can see that if there's no TX/RX activities, WIFI is not connected to a SSID, or that the actual WIFI device has a status fault, then bringing the interface down would make sense.

RE: nRF7002 - wlan0 interface goes down after repeated making HTTP requests

Elfving — Mon, 07 Jul 2025 11:53:44 GMT

Hi Tom,

Do you have any error log of this? What NCS version are you using - or are you saying that this is vanilla zephyr?

I guess this could be SHEL-3596. Having a look at the shutdown sample might also be helpful.

Regards,

Elfving