Zephyr Console on Adafruit Feather nrf52840 connected via SWD to nrf52840dk

[HeneryH]

I have a Thread bench-top environment set up that includes

• One nrf5340dk flashed with the openthread coap_server firmware build and flashed on 1.8 via Visual Code
• Two nrf52840dk's flashed with openthread coap_client firmware build and flashed on 1.8 via Visual Code
• One Adafruit Feather Feather nrf52840 Express coap_client firmware built with Visual Code and flashed with the nRF Desktop Flasher
• One nrf52840dk flashed with the RCP formware and paired with an OTBR on Pi.  OR flashed with the TTM firmware and viewed on TTM.

Loading the sample firmware on the coap_cients and servers works fine.  They all join using the hardcoded credentials.

I can use OTBR to join and view the network.

GREAT!

Now I am trying to use my own secure network and credentials.

I think i need to get the unique EUID for each board.

For each of the Dev Kits, I can use a serial console to connect UART to the DKs and see the Zephyr console.  I can issue the "ot eiud" command and get that SoC's id.

GREAT!

Now I am trying to connect to the Adafruit Feather which was flashed via the SWD cable on one of my DKs.  I know that device is running but I can't figure out how to connect interactively to it (cli) to learn its euid or issue ot commands.

The Adafruit docs seem to indicate that I can use the onboard usb port, but that isn't registering with the host (win11) as a serial port.

I tried to connect to the associated DK serial port but that seems to still be linked to the onboard SoC nrf.

The coap_client is the same code running on all of the dk clients but has the board configuration set to the feather board type.

Any ideas or hints to figure out how to interact with the Feathers?

Thanks

[Jørgen Holmefjord]

Hi,

I assume you are referring to the "ot eui64" command? I could not find any commands named "ot eiud".

There is no UART interface available through the debug connector. You will either have to use the SWD interface, or the UART interface of the Adafruit Feather nRF52840 Express externally through a UART-to-USB adapter.

It is possible to enable RTT support for the Shell, by setting "CONFIG_SHELL_BACKEND_RTT=y" in your prj.conf file. You can then send the shell commands from an RTT client, like J-Link RTT Viewer (Enable: "Input->Sending...->Send on Enter for erase of reading):

Depending on which target you built for when building the firmware for the Feather, the UART will be available on some of the GPIOs of the board. You can connect the UART TX/RX pins to an UART-to-USB cable, or to P0.06/P0.08 pins of an (erased) nRF52840 DK, which will allow you to use the Virtual COM port functionality.

One final option is to use the USB port of the Feather. It looks from the schematics as this is connected directly to the native USB port of the nRF52840, which means you will have to enable USB support in the application. I can't find any simple configs to enable USB CDC ACM support for the shell, but you may be able to achieve it following the procedure described in this thread.

Finally, the EUI64 is by default generated from Nordic's MA-L + the random number stored in FICR->DEVICEID[n] registers. You can read it out using nrfjprog:

Best regards,
Jørgen