Thread co-processor sample does not work on nRF52840 board (using ot-cli tool)

[Marco Russi]

Hello,

I have been trying to run the Thread co-processor sample for a whole day with no success. I have tried everything including the steps from OpenThread website. I originally wanted to run a Thread Border Router but now I'd just be happy to create a Thread network with a nRF52840 DK board.

I have built the Thread co-processor sample as below:

west build -b nrf52840dk_nrf52840 -d build_nrf52840dk_nrf52840 -- -DCONF_FILE=prj.conf -DOVERLAY_CONFIG=overlay-rcp.conf

and flashed the board:

west flash --erase --build-dir ./build_nrf52840dk_nrf52840/

I then verified the flash memory and it is ok.

This is the git commit id of the sample d391915ad

Now, when I run the ot-cli tool this is what I get:

sudo ./build/posix/src/posix/ot-cli 'spinel+hdlc+uart:///dev/ttyACM0?uart-baudrate=1000000?uart-flow-control' --verbose
./build/posix/src/posix/ot-cli[19719]: Running OPENTHREAD/thread-reference-20200818-ncs1-rc3-560-g02e61a2ed; POSIX; Apr 3 2022 14:31:53
./build/posix/src/posix/ot-cli[19719]: Thread version: 2
./build/posix/src/posix/ot-cli[19719]: 49d.17:45:10.943 [CRIT]-PLAT----: Too many rcp failures, exiting
./build/posix/src/posix/ot-cli[19719]: 49d.17:45:10.943 [CRIT]-PLAT----: BSD TCP function() at radio_spinel_impl.hpp:2249: Failure

I have added the "?uart-flow-control" parameter despite it is not present in your guide here https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/ug_thread_tools.html#running-the-openthread-posix-applications and the sample has uart flow control enabled. Anyway it does not work even without the uart flow control parameter. 

I ran out of idesa... please help.

Thank you. 

[Jørgen Holmefjord]

Hi,

Which commit in the OpenThread repository are you running ot-cli from? The reference date sounds a bit old. If the ot-cli and RCP versions are far apart, there may be differences in the protocol that causes issues. 

Have you tried with the nRF Connect SDK v1.9.1 release instead of the later commit? Working on the latest commits may cause more issues since everything is not tested thoroughly like the releases.

I also found a recent GitHub issue describing the same errors, which may be related.

Best regards,
Jørgen

[Marco Russi]

I have noticed that I used prj.conf when compile so I tried without it and added -DCONFIG_OPENTHREAD_THREAD_VERSION_1_2=y

as specified in your guide. I have also disable MSD in the Segger Jlink.
No luck though...

So the compile command is:

west build -p always -b nrf52840dk_nrf52840 nrf/samples/openthread/coprocessor/ -- -DOVERLAY_CONFIG="overlay-rcp.conf" -DCONFIG_OPENTHREAD_THREAD_VERSION_1_2=y