Trouble flashing nrf52840 dongle (Peripheral UART sample)

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

Hieu — Mon, 17 Mar 2025 13:58:43 GMT

Hi olalonde and James168,

My colleague Vidar shared the following past case, which I believe is the same issue.

nRF52840 dongle, BLE peripheral_uart example, SDK migration from 2.6.0 to 2.9.0

Please refer to that case for more explanation and a sample code that fixes the issue.

Hieu

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

Hieu — Fri, 14 Mar 2025 16:47:43 GMT

I don't have a nRF52840 dongle right now, so right now I only have the nRF52840 DK, which runs the LBS sample from v2.9.0 fine. I will check the dongle next week.

As for having to comment out UART lines to work, could you give me more details? It is most likely related to the fact that on the dongle, you actually use USB CDC ACM for serial, rather than true UART interface.

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

James168 — Fri, 14 Mar 2025 07:17:01 GMT

Not sure related to this ticket, it's about mcuboot, I don't have time to read it detail.

After upgrading mcuboot, the device crashes upon power-up - Nordic Q&A - Nordic DevZone - Nordic DevZone

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

olalonde — Fri, 14 Mar 2025 02:43:15 GMT

You're right, I commented out some UART related stuff in peripheral_uart and it ended up working on the dongle. (with the pm_static_nrf52840dongle_nrf52840.yml file though because I am using the bootloader to flash)

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

James168 — Thu, 13 Mar 2025 06:26:06 GMT

Hi,

1) peripheral_lbs v2.7.0 is normal, but v2.9.0 can't advertise in dongle. I guess nordic make something wrong in the new NCS version.

I attach the hex file for test.

devzone.nordicsemi.com/.../zephyr_5F00_v270_5F00_lbs.hex

2) peripheral_uart is failed to advertise in both NCS version for dongle, I guess maybe need to modify main.c due to UART function, but I don't have time to trace now.

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

Hieu — Wed, 12 Mar 2025 22:33:33 GMT

Hi olalonde,

That is really quite strange. I just built the Peripheral LBS sample myself, and the memory layout is as expected. The application starts at 0x00001000, which is the only requirement for the dongle to work. I unfortunately don't have a dongle with me so I couldn't verify that it works yet.

Do you have the hex file of the Peripheral LBS sample when it didn't work? Also, what SDK version were you using?

As for Peripheral UART, how is it not working? Are you able to see its advertisement with the nRF Connect app, for example?

Hieu

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

olalonde — Wed, 12 Mar 2025 17:20:52 GMT

Update2:

I managed to get the "Bluetooth: Peripheral LBS" sample to work by copying the pm_static_nrf52840dongle_nrf52840.yml file from the "Bluetooth Mesh light fixture sample" sample to the root of the project.

However, the "BLE Peripheral UART" sample is still not working as expected.

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

olalonde — Wed, 12 Mar 2025 16:18:55 GMT

Update:

I also tried to build and flash the "Bluetooth: Peripheral LBS" which according to its documentation supports the nrf52840 dongle. But after I flash nothing happens although the documentation states that the LED should be blinking.

Here's the steps I followed

1) I created a new application from sample

2) Create a build configuration, keep all defaults except for the board which I change to nrf52840dongle/nrf52840.

3) Click build.

4) Put the dongle in bootloader mode (red led fading in/out).

5) Open the Programmer, select device, add file, select build/merged.hex, click "Write".

I tried with two different dongles to make sure it wasn't a hardware issue.

What am I doing wrong?

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

olalonde — Wed, 12 Mar 2025 03:35:45 GMT

Is it possible to keep the bootloader? I think it would be better because I don't have a J-Link debug probe.

RE: Trouble flashing nrf52840 dongle (Peripheral UART sample)

James168 — Wed, 12 Mar 2025 03:29:23 GMT

Do you want to keep the original bootloader of 52840 dongle or not?

check this,

devzone.nordicsemi.com/.../how-to-generate-nrf52840-dongle-hex-file-with-using-external-j-link-to-program-and-run-directly