nrf70 RPU never sends results back

RE: nrf70 RPU never sends results back

Buster Nielsen — Tue, 31 Mar 2026 10:42:00 GMT

Hi,

We found it that the some of the WiFi modules had been damaged during manufacturing, which caused the issue.
Thank you for your time and help.

Best regards.

RE: nrf70 RPU never sends results back

Samruddhi Jadhav — Tue, 31 Mar 2026 10:38:57 GMT

Hi,

Have you had the chance to test with the attached folder in my previous message?

Best Regards,

Samruddhi

RE: nrf70 RPU never sends results back

Samruddhi Jadhav — Wed, 25 Mar 2026 11:24:17 GMT

Hi,

Please see the the attached folder of NCS 3.1.1 based firmware binaries with BLE Coex internally disabled. Can you please try with these and see if it fixes the issue?

devzone.nordicsemi.com/.../ncs3.1.1_2D00_nocoex_2D00_fwbins.zip

Best Regards,

Samruddhi

RE: nrf70 RPU never sends results back

Samruddhi Jadhav — Wed, 18 Mar 2026 12:09:30 GMT

Hi,

Apologies for the delay. We have taken a look at the schematics given in the previous message. It still seems that the COEX_REQ pin is floating and this is a common reason which causes issues. Can you try to make sure it is pulled down or GND on one of the boards? Let me know if that solves the issue.

Best Regards,

Samruddhi

RE: nrf70 RPU never sends results back

Buster Nielsen — Mon, 16 Mar 2026 13:28:40 GMT

One additional detail: passive scans work without any issues. The problem only occurs during active scans.

RE: nrf70 RPU never sends results back

Buster Nielsen — Mon, 16 Mar 2026 12:47:27 GMT

Hi,

The schematic is shown in the attached photos and linked again here. We're using the AN7002Q module. The COEX_REQ pin is on the bottom of the module, which is surface-mounted, so we can't access it.

I tested this by building the Wi-Fi shell for the nRF54L15DK with the nRF7002EB2 shield and left the COEX pins disconnected (floating), matching our custom board setup. Wi-Fi still worked fine.

The documentation doesn't mention floating COEX pins as a problem, and in my testing they don't actually float, COEX_REQ gets pulled to GND when unconnected, and GRANT is pulled to IOVDD.

So I don't believe the COEX pins are the issue here.

RE: nrf70 RPU never sends results back

Samruddhi Jadhav — Mon, 16 Mar 2026 07:03:31 GMT

Hi,

On the nrf70, the issue seems to be that the COEX_REQ pin is floating. Is it possible for you to send the schematics specifically for this part? If the pin isn't being used, you can try to modify the non-working board so that it grounds this pin. Can you check if this works?

Best Regards,

Samruddhi

RE: nrf70 RPU never sends results back

Buster Nielsen — Fri, 13 Mar 2026 12:57:20 GMT

Coex is not enabled in C7/nrf5340_cpuapp_common.dtsi.

And the build .config confirms that it is in fact disabled for this build.

# CONFIG_NRF70_SR_COEX is not set

And we can't put a probe on it because it's not connected to anything as can be seen from the attached schematics.

RE: nrf70 RPU never sends results back

Samruddhi Jadhav — Fri, 13 Mar 2026 08:43:35 GMT

Hi,

On your custom board, can you please check coex request pin state and let me know?

Best Regards,

Samruddhi

RE: nrf70 RPU never sends results back

Samruddhi Jadhav — Wed, 11 Mar 2026 17:44:43 GMT

Hi,

I am working on this issue with the team and will get back to you by this week with an update.

Best Regards,

Samruddhi