The selected HEX file appears to be invalid for Thingy:91 MCUboot DFU

[Thomas Halwax]

Hi,

I have a Thingy:91 v 1.0.0 which runs fine with the provided asset tracker firmware thingy91_nbiot_dfu_2020-04-29_bc7ade8b.hex. Cloud connect also is fine.

I managed to compile (SDK v 1.3.1) the asset tracker sample application which produces a number of hex files. merged_domains.hex seems to be the right file to upload to the device. But when I try to do so nRFProgrammer complains about "The selected HEX file appears to be invalid for Thingy:91 MCUboot DFU".

In contrast to the file provided by Nordic my hex file also contains a MBR.

Writing the merged_domains.hex to the device succeeds but the applications does not start afterwards. Can you please give me a hint what to do to make this work?

Thanks in advance,

Thomas

[Øyvind]

Hello Thomas, 

Are you programming the device using MCUboot? If so, the app_signed.hex is correct version to use. See documentation on Building and programming from source code.

If you are programming using an external JLink programmer, then merged.hex is correct version. 

Edit: Also, please be sure to read the Firmware documentation for Thingy:91

Kind regards,
Øyvind

[Thomas Halwax]

Hello Øyvind,

thank you for your response. I can confirm that using app_signed.hex works which brings me a step further. Also thank you for referencing the documentation, I promise to switch from experiment first to read first ;-)

Thanks and best regards,

Thomas

[Øyvind]

Thomas, I'm glad to hear!