nRF91 DK not recognizing/flashing properly the host board through Debug Out pin

[Saketaram]

Hi,

I used nRF91DK for almost 2 months non stop to debug the final nRF91 based board for our air quality monitoring hardware to fight the propagation of Covid virus.

But since the 1st January, when I connected to DK, without any host board connected vis Debug Out pins, I got this in nRF Programmer (serial number of DK, and name with REV1 at the end):

When I connect a host board to DK (SW11=3V, SW5=nRF91), I usually see the host board to select. But now I only see the same serial number of 9160DK, ending with "REV2":

And the RTT Viewer is showing this (no LED lit ON on the host board as it is supposed to be)

Here is how the host is connected to DK:

My colleague in charge of embedded software told me it might be an overheating issue for nRF9160DK (#33)

The related ticket suggests to press RESET button to see "Bootloader"but my DK always shows JLINK, so I am lost on how to make it come back to work

Let me know what you think about this. We are in hurry to fight covid with our technology which is in high demand.

Thanks again,

Saketaram

[Saketaram]

Hi Priyanka,

We are now working with

• nRF Connect v3.9.3
• SDK v1.8.0
• nRF Command line v10.15.1
• ToolChainManager v0.10.1
• JLink v7.58b
• McuBoot v1.7.1

It seems the issue stands on the mcuboot, that allowed proper functionning until last December, but didn't work anymore since January 2022 when using nRF command line: both nRF Programmer and west flash say host board was flashed but there is no RTT Viewer log on the recently flashed boards. But the previously flashed boards show the logs. And when the host board is updated through fota (with bin file from the cloud, not locally flashed) the host board also show the logs on RTT viewer for the connected board through DK.

Which version of mcuboot is compatible with the other parts which were recently upgraded? We also found this ticket on mcuboot that might be related: https://github.com/mcu-tools/mcuboot/issues/1164

What alternative do we have on mcuboot for fota. Could we use secure bootloader? Is it consistent in its performance?

Which nRF command line should we use?

Thanks for your prompt expertise.

[Priyanka]

Hi,

Could you try 

nrfjprog --program C:/meo/application/meo_mini_firmware/build/zephyr/merged.hex --recover -f NRF91

You should be able to reprogram the device this way.

Regards,

Priyanka