wifi_supplicant: Failed to add iface wlan0 and Wi-Fi connect failed (-134) on nRF9160 + nRF7002

[Krishhh]

Hi,

I am using a custom nRF9160 board with the nRF7002 Wi-Fi chip via SPI, running NCS v2.9.2. My goal is to connect to a Wi-Fi network.

However, during initialization, I see the following logs:
[RX] - wifi_supplicant: Failed to add iface wlan0
[RX] - Starting Wi-Fi connection...Wi-Fi connect failed (-134)

Questions:

1. What are the common causes for Failed to add iface wlan0 in NCS v2.9.2?

2. Could this be related to device tree configuration, heap/buffer sizing, or Kconfig options?

3. Are there any recommended example prj.conf / DTS settings for nRF9160 + nRF7002 that reliably connect to a WPA2 AP?

4. Is it possible to achieve HTTPS certificate-based communication with the nRF9160 + nRF7002 combo over Wi-Fi only (without LTE)?

Any guidance or reference to working samples would be greatly appreciated.

[Elfving]

Hi,

I am not immediately sure what causes this to happen. I can address your questions, though first of all: are you seeing these issues with default samples as well? And are you seeing these issues with DKs + expansion boards?

What first comes to mind is that this could be related to issues commissioning the nRF7 (ie writing to OTP etc.), which is already done on the DKs, which is why it is often missed by customers.

Regards,

Elfving

[Krishhh]

Hi, thanks for the response.

This is a fully custom board that we designed and developed (not a DK). The board integrates an nRF9160 + nRF7002 over SPI.

We have already provisioned the nRF7002, and scanning works fine (we can see available APs). However, when attempting to connect, the connection fails with the following logs:
wifi_supplicant: Failed to add iface wlan0
Starting Wi-Fi connection...
Wi-Fi connect failed (-134)

So the issue is not with scanning, but specifically with establishing the Wi-Fi connection.