No response from nRF52820 when DFU is attempted again

[Louis_263]

Hello everyone,

I have successfully managed to perform a DFU with a DFU package consisting of an app and a softdevice. I wanted to test what happens when I manually cancel the DFU and then try to start a new DFU.
After I cancelled the DFU of the app and restarted the DFU, the DFU works without any problems and the app starts as expected.
However, after I cancel the DFU of the softdevice and restart the DFU, there is no response from the nRF in the DFU after a certain point.

This is the log where the DFU of SD + App worked:

log_ok.txt

This is the log where the DFU of SD + App did not work (after I cancelled the DFU of the softdevice manually):

log_fail.txt

In the log where the DFu didn't work, I see that flash memory is written to from address 0x27000. However, this is the area of the application. I would have expected that first in the area of the softdevices is written, because this was also so in the log where the DFU has worked.
Is this possibly a bug?

Best Regards

Louis

[Louis_263]

Hi Vidar,

Thanks for your fast answer Currently there is probably no fix for this since no new SDK has come out yet, right?

[Vidar Berg]

Hi,

No problem. Yes, you are right, we currently do not have a fix for this available. It looks like it should be easy enough to fix, but I would be hesitant to make changes to critical changes to a critical part of the validation step without extensive testing and validation. I think it is safest to use the workaround for now. It should be possible to automate this recovery procedure without any user intervention.