Thingy52 DFU fails with message "FW version failure (Code = 5)", using nrfutil and nRF Connect

[Till]

Hi all,

I've got a single Thingy:52 (FW v2.1.0), and no DK. I'm trying to upgrade its firmware through nRF Connect on Android, but keep on running into a FW version failure (Code = 5) error whilst doing the DFU.

Can anyone enlighten me whether the following workflow is currently supported, and if so, what I am doing wrong? Any hints will be much appreciated and I'll update my question if you need any further details.

Abbreviations:

• APP - my firmware application code
• BL - the bootloader
• SD - the s132 Soft Device

The APP, BL and SD have been taken or compiled from this Github commit of the Thingy SDK v2.1.0.

Suggested Workflow (paths truncated for readability):

1. Compile the APP, cd <ProjectRoot>/project/pca20020_s132/armgcc && make -j. This builds nrf52832_xxaa_s132.hex.
2. Generate BL settings, nrfutil settings generate --family NRF52 --application <APPDir>/armgcc/_build/nrf52832_xxaa_s132.hex --application-version 1 --bootloader-version 2 --bl-settings-version 1 settings.hex
3. Generate key pair and compile the BL, cd <ProjectRoot>/project/bootloader_secure/pca20020/armgcc && make -j. This builds nrf52832_xxaa_s132.hex (same name as APP, but different hex content).
4. Merge BL with settings, mergehex -m <BLDir>/armgcc/_build/nrf52832_xxaa_s132.hex settings.hex -o bl_with_settings.hex
5. Generate DFU package, nrfutil pkg generate --application-version 1 --bootloader-version 2 --hw-version 52 --bootloader bl_with_settings.hex --softdevice <ProjectRoot>/external/sdk13/components/softdevice/s132/hex/s132_nrf52_4.0.2_softdevice.hex --application <APPDir>/armgcc/_build/nrf52832_xxaa_s132.hex --sd-req 0x98 --sd-id 0x98 --key-file private-key.pem thingy-dfu.zip
6. Upload thingy-dfu.zip to internal phone memory and perform nRF Connect DFU, which results in the following error: [DFU] Remote DFU error: EXTENDED ERROR [DFU] Details: FW version failure (Code = 5). See the full nRF Connect log here.

So supposedly something's wrong with my version numbers. I've tried all sorts of combinations, from APP=BL=0, to APP=BL=10.

Thanks!

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Update: The nRF52 DK has arrived and flashing, in order, the SD, APP and BL (merged with the settings file as per above) via nRFgo Studio on Windows works. For that I use the Segger debug connector as suggested in this answer, and modify the Bootloader to accept custom FW as suggested here, including the const modification.

[Bjørn Kvaale]

So basically everything works fine when you do dfu via the nrf52 and swd cable, but not via OTA-DFU, right? You could try to use the pca20020_debug version of the bootloader_secure (see step B: Build the bootloader). This should avoid version checking. For more information on version checking, this link could be helpful.

[Till]

Hi Bjørn, thanks for your comment! Yes, that's correct. I've been flashing the device through the nRF52 DK without any problems. (It's great that the DK automatically switches to "passthrough" as soon as you connect an external device via SWD). If I find the time I'll compile the bootloader_secure - do you have a Makefile for armgcc, for compiling it on Linux? And secondly, I was going to investigate whether modifying the Bootloader to accept custom FW (as mentioned in my update above) makes a difference... could that be the culprit?

[Bjørn Kvaale]

Hi Till, there's a makefile located under project\bootloader_secure\pca20020\armgcc in the Thingy FW. Is this fine or did you want to use the debug bootloader? I don't think you will need to modify the bootloader. This link explains what steps you need to take to make OTA-DFU work on the Thingy:52. In other words, this might be the reason you are getting the error.