What is the compatitble SoftDevice version for nRF52840 Dongle? My aim is to configure the nRF52840 Dongle and to advertise the packets.

[Venu Madhav]

What is the compatitble SoftDevice version for nRF52840 Dongle? My aim is to configure the nRF52840 Dongle and to advertise the packets.  

[Einar Thorsrud]

Hi,

Any SoftDevice that is compatible with the nRF52840 can be used with the nRF52840 dongle. The key is that you use a SoftDevice that is compatible with your firmware (when you build bluetooth firmware using the osl nRF5 SDK, that includes header files for a specific SoftDevice version).

PS: If you add the accompanying SoftDevice hex to the programmer app, you will not have to specify the SoftDevice version

PSS: Note that this is only relevant for the old nRF5 SDK, the nRF Connect SDK does not use the SoftDevice (the SoftDevice Controller used there is different and included in the application binary once the application ins built).

[Mmes]

Can you elaborate? The merged.hex produced by nrf-connect-sdk(3.1.1) when building the nRF Desktop sample with board nrf52840dongle is not writable with the Programmer(4.6.2).

Trying to program the merged.hex results in the popup shown by Venu Madhav above. It's not clear what the "correct" SDev even is, or why it's asking.

[Einar Thorsrud]

Hi,

That is a special case, as with nRF Connect SDK there is no SoftDevice. Moreover, as the nRF52840 Dongle has an nRF5 SDK USB bootloader, the application needs to start at address 0x1000, and be built with CONFIG_BOARD_HAS_NRF5_BOOTLOADER=y and CONFIG_FLASH_LOAD_OFFSET=0x1000. That is not the case if you build nrf_desktop even with dongle as target by default, so the firmware generated is not compatibler with being programmed like this (it would requier attaching an external debugger). So you need to modify the configuration to add the mentionned configurations, but this is also a bigger task as it affects the bootloader etc, and there is a reason this choise was made for nRF desktop.

So in short, if you want to use the dongle for nRF destkop, program it with an external programmer (you can solder on programming header on the back side of the dongle). For other nRF Connect SDK projects this will work out of the box with the nRF52840 dongle using the Programmer app.

[Mmes]

Thanks for the prompt response, I vaguely came to the same conclusion when I set CONFIG_BOARD_HAS_NRF5_BOOTLOADER + CONFIG_FLASH_LOAD_OFFSET and flashing with `nrfutil device program ...` still failed*.

Is there an "out of box" project that will let me flash the dongle as a LLPM dongle?

*As an aside, `nrfutil device program` cannot program dfu_application.zip produced by nRFConnect. it does not know how to parse the metadata.

[Einar Thorsrud]

Hi,

The nRF Desktop reference design has a DFU architecture that does not work with the dongle as is, and there is no conrresponding sample that does it. If you do not need this as part of a nRF Desktop setup but want to test LLPM only with the nRF52840 dongle, you can use the LLPM sample.