Blocked in DFU mode after an upgrade

[Etienne]

Hi all, 

I have an issue on my device. We have implement OTA update but sometimes, the nfr stucks on DFU mode after the update. Even if the update is succesfull.

We use the nrf 52840 with SDK15.3 and S140 softdevice. 

If we use nrf connect app after the device was stuck on DFU with the same package the update works well and the device reboot normaly. 
We don not understand why sometimes the device is stuck in DFU mode. 

Is there a way out on the NRF connect app tu restart the nrf52840 ? 

Best regards

Etienne

[Edvin]

Hello,

If we use nrf connect app after the device was stuck on DFU with the same package the update works well

Did you use the nRF Connect app the first time as well? Or are you using a custom app?

Can you try to use the debug bootloader, located in:

SDK\examples\dfu\secure_bootloader\pca10056_ble_debug

And monitor the RTT log from the nRF52840? What does it say when it fails?

Best regards,

Edvin

[Etienne]

Hi, 

We are using a custom app based on SDK v2.0.3. 

We are using NRF Connect to detect DFUTarg and upload the new firmware again and it work well.

I will try with the debug bootloader to see what happend. 

Regards, 

Etienne 

[Edvin]

Ok, I see. Does it work if you use nRF Connect for Android directly? Just to see if the issue is pointing to the Android app or the nRF chip...

Either way, using the debug bootloader project files can shed some light on what part that fails during the DFU.

BR,

Edvin

[Etienne]

We just try both to be sure and we have the same result with both, Custom app and NRF Connect for Android app.

The strange thing is we try to send the same package with SD+BL + APP while the device was stuck in DFU mode and it works well the second time. 

I try to use the debug bootloader project but I do not reproduce the issue... 

So I do not know how to procced to debug this issue.

Regards, 

Etienne 

[Edvin]

Are you able to reproduce the issue on a DK + nRF Connect for Android? If so, I can try to reproduce the issue here locally, and see if I can find anything.

If so, please send the bootloader and application projects that you are using. You can strip out the private and public keys that you are using for security concerns. I can generate my own key pairs.

Best regards,

Edvin

[Edvin]

Please see the message I sent you in the chat regarding the files that you sent me.

Another thought is: Did you try to send the DFU image using nRF Connect for Desktop?

While I understand that this is not what you want to do in the end, it may be useful for debugging purposes. Does it work there? If not, what does it say? If it doesn't work, it is actually a good thing, because then we would know that the DFU server and the image transport will be the exact same for me and you. Then we only need to reproduce the issue on a DK.

Best regards,

Edvin

[Etienne]

Hi, 

We may find something on the verification of the settings that does not goes well and write lot of settings page and erase bank size, bank crc and bank code values so the application can't reboot after this operation. 

We keep looking aroud this. 

Thanks for your help.

Best regards, 

Etienne