How to use WDT with System ON sleep

RE: How to use WDT with System ON sleep

Kazi Afroza Sultana — Wed, 20 Nov 2024 08:35:12 GMT

It's really great that you found the root cause. I was thinking to tell you to set a very long WDT timeout and wake up often enough to handle it. Whatever you solved the issue and shared with the community. Thank you once again.

RE: How to use WDT with System ON sleep

Arthur J Sary — Tue, 19 Nov 2024 19:24:55 GMT

Thanks for your help, the error was caused by a timer that generates an interrupt that remained enabled during sleep. Every time the interrupt was triggered, the WDT was enabled again until reset.

RE: How to use WDT with System ON sleep

Arthur J Sary — Tue, 19 Nov 2024 19:23:39 GMT

Thank you to everyone who helped! I discovered that the issue was actually caused by an interrupt from a timer that was enabled during the sleep state. When the timer interrupt triggered, it caused the WDT to resume its operation, and over time, this led to the WDT eventually timing out and resetting the system.

For anyone experiencing a similar problem with the WDT resetting during sleep, I recommend checking if all interrupts are properly disabled during the sleep state (at least those that are not meant to remain active). This can help prevent unexpected behavior.

RE: How to use WDT with System ON sleep

Kazi Afroza Sultana — Tue, 19 Nov 2024 18:38:32 GMT

Hello,

The WDT_OPT_PAUSE_IN_SLEEP should WDT paused in sleep. It should propagate to the SLEEP field in the CONFIG of the WDT https://docs.nordicsemi.com/bundle/ps_nrf52840/page/wdt.html#ariaid-title14.

You may try to verify with a debugger that this field is actually set correctly?

RE: How to use WDT with System ON sleep

Arthur J Sary — Fri, 15 Nov 2024 18:45:13 GMT

I am start WDT with the WDT_OPT_PAUSE_IN_SLEEP option, where it should stop working during sleep. I can't show the output, as I was testing on a custom board that the RTT LOG does not appear after the reset.
On nRF52840 it is not possible to disable WDT after it has been initialized. I tested the system without starting WDT and everything worked as expected.

RE: How to use WDT with System ON sleep

Kazi Afroza Sultana — Fri, 15 Nov 2024 05:55:18 GMT

Hello,

I think it is still working on system on sleep. Maybe you are thinking of system off? Can you show the output log? Or You can try to disable the watch dog timer and see if you can see any difference?

RE: How to use WDT with System ON sleep

Arthur J Sary — Wed, 13 Nov 2024 13:11:28 GMT

I'm working with toolchain v2.7.0 and SDK v2.5.2, in these versions there is no such config. The configurations that exist on WDT are CONFIG_WDT_DISABLE_AT_BOOT, CONFIG_WDT_LOG_LEVEL_DBG and CONFIG_WATCHDOG.

RE: How to use WDT with System ON sleep

Kazi Afroza Sultana — Wed, 13 Nov 2024 08:20:24 GMT

Hello,

Is this config set in your config file CONFIG_WDT_NRFX_RUN_DURING_SLEEP=y?