NRF52840 Dongle NCS3.1.1 boot problem

RE: NRF52840 Dongle NCS3.1.1 boot problem

Amanda Hsieh — Mon, 03 Nov 2025 15:57:19 GMT

Happy to see the good news. 🙂

RE: NRF52840 Dongle NCS3.1.1 boot problem

ChrisRu — Sun, 02 Nov 2025 01:03:49 GMT

Good Morning.
I have it fixed.

"--no-sysbuild" did the magic and the nano-33-ble stop boot-loop and nrf52840dongle have ttyACM0/1 up.
west build -d ../build/arduino33server/ -b arduino_nano_33_ble $snippets --no-sysbuild -p -- -DCONF_FILE="prj.conf nano33.conf"

west flash -d ../build/arduino33server -r bossac --bossac-port=/dev/${port}

[00:00:00.010,070] <inf> ieee802154_nrf5: nRF5 802154 radio initialized
[00:00:00.068,511] <err> net_openthread_platform: Failed to submit work to queue, error: -19
[00:00:00.079,925] <inf> fs_nvs: 8 Sectors of 4096 bytes
[00:00:00.080,535] <inf> fs_nvs: alloc wra: 5, bd0
[00:00:00.081,176] <inf> fs_nvs: data wra: 5, a60
[00:00:00.102,172] <inf> net_openthread_platform: State changed! Flags: 0x101fc710 Current role: disabled Ip6: down
*** Booting nRF Connect SDK v3.1.1-e2a97fe2578a ***
*** Using Zephyr OS v4.1.99-ff8f0c579eeb ***
[00:00:02.407,012] <inf> coap_server: Starting

That was a hard nut!

RE: NRF52840 Dongle NCS3.1.1 boot problem

ChrisRu — Sat, 01 Nov 2025 08:07:04 GMT

I'd followed your suggestion and clone the sdk-nrf.
I build the cli sample on the command line using west build -d build_dongle -b nrf52840dongle/nrf52840
which builds without any errors or warnings.

I set the dongle to DFU mode, the LED is flashing. OK
But when I run west flash -d build_dongle flash failed: no boards found

-- west flash: using runner nrfutil
runner_config: RunnerConfig(build_dir='/home/chris/project/Tentacles/Harvester/build/nrf52dongleserver/coap_server', board_dir='/home/chris/Desktop/workbench/project/Tentacles/ncs/zephyr/boards/nordic/nrf52840dongle', elf_file='/home/chris/project/Tentacles/Harvester/build/nrf52dongleserver/coap_server/zephyr/zephyr.elf', exe_file=None, hex_file='/home/chris/project/Tentacles/Harvester/build/nrf52dongleserver/merged.hex', bin_file='/home/chris/project/Tentacles/Harvester/build/nrf52dongleserver/coap_server/zephyr/zephyr.bin', uf2_file=None, mot_file=None, file=None, file_type=<FileType.OTHER: 0>, gdb='/opt/gnuarmemb/arm-gnu-toolchain-14.3.rel1-x86_64-arm-none-eabi/bin/arm-none-eabi-gdb', openocd='/usr/bin/openocd', openocd_search=None, rtt_address=None)
-- runners.nrfutil: reset after flashing requested
runners.nrfutil: nrfutil --json device list
runners.nrfutil: Found boards: []

I double checked it with (obmit --json) board is here.

$ nrfutil device list
E1CF80C8ACF9
Product Open DFU Bootloader
Ports /dev/ttyACM0
Traits serialPorts, nordicUsb, nordicDfu, usb

Supported devices found: 1

I was not aware that there is something broken with the west scripts from zephyr because I use a build script which doing the two steps a) nrfutil to create a zip and b) call nrfutils to write it.

nrfutil nrf5sdk-tools pkg generate \
--hw-version 52 \
--sd-req=0x00 \
--application $build_path/coap_server/zephyr/zephyr.hex \
--application-version 1 \
$build_path/nrf52dongle.zip

nrfutil device program --firmware $build_path/nrf52dongle.zip --traits nordicDfu

Did I do something wrong in my build script?
And why is the west flash failing? Missing patch in the zephyr script directory?

west --version
West version: v1.5.0

RE: NRF52840 Dongle NCS3.1.1 boot problem

Amanda Hsieh — Fri, 31 Oct 2025 19:32:41 GMT

Could you run and test this sample https://github.com/nrfconnect/sdk-nrf/tree/v3.1.1/samples/openthread/coprocessor or this https://github.com/nrfconnect/sdk-nrf/tree/v3.1.1/samples/openthread/cli for nRF52840dongle? If it can work without issue, you can refer to the settings for the nRF52840 Dongle.

RE: NRF52840 Dongle NCS3.1.1 boot problem

ChrisRu — Fri, 31 Oct 2025 08:21:59 GMT

If I compare nrf52840 pinctrl definition (using group1 & group2) the arduino pinctrl uses only group1 for the uart0, so my first thinking of a wrong dts is a dead end.
(I use uart0 on the thumbs and try to read the debug output messages via serial not cdc-acm-usb)

RE: NRF52840 Dongle NCS3.1.1 boot problem

ChrisRu — Thu, 30 Oct 2025 23:33:11 GMT

Thank you for your answer.

All the builds was working fine with NCS 2.9, not a problem with bossac. And I'm not using mcuboot.

The problems start for the thumbs after upgrade to NCS 3.1.1

Maybe something with the zephyr.dts I spotted a single line for uart0 default and sleep where I expect two. One for tx and one for tx pin.

Let me post that part later.

RE: NRF52840 Dongle NCS3.1.1 boot problem

Amanda Hsieh — Thu, 30 Oct 2025 17:01:56 GMT

Hi,

You can check this post for the nRF52840 Dongle. As for Arduino Nano 33 BLE, it requires a specific variant of the bossac tool for flashing. Using the wrong version (such as the one from Zephyr SDK instead of the Arduino IDE) can result in failed or partial programming, leading to boot loops or USB disconnects. Ensure you are using the Arduino-provided bossac and specify the correct port. See Zephyr Docs: Programming and Debugging Arduino Nano 33 BLE.

Regards,
Amanda H.