How to use the watchdog when DFU

[roy756456625]

Hi

I opened the Watchdog in the user application,and do nothing in the bootloader.Then when I use DFU,the CPU reset appears.How can I to deal with it?

And when I upgrade willful termination APP(nRF Toolbox),the CPU(nRF52832)is down,and can't work.Do you have any suggestions on how to solve this fault tolerance?

Thank you!

[bjorn-spockeli]

You'll have to "feed" the watchdog in the bootloader, i.e. call

NRF_WDT->RR[0] = 0x6E524635UL;

in order to prevent the watchdog timer from timing out and resetting the chip.

-Bjørn

[Jarmo]

How to actually do that? Where is the loop I can put that watchdog feeding call in your bootloader_secure? If I remember right, there is an event loop, yes. But might it be that BT events are coming so rarely that the watchdog bites before the it is feeded next time?

Furthermore, can I check in the bootloader somehow, if the watchdog is running or not?

And in the first place, I don't really understand why watchdog is not stopped when the system resets. There's no any clever reason for that kind of design.