Watchdog timer unexpected Reset in nrf52810

RE: Watchdog timer unexpected Reset in nrf52810

Einar Thorsrud — Tue, 21 Jan 2020 08:02:50 GMT

Hi,

I suspect your main loop never runs after the first to sd_app_evt_wait(). This is because SoftDevice will check if the interrupt was for itself or for the application, and only forward it to the application if it appropriate. So my theory from yesterday still holds based on this code (though I do not see your whole application). You can easily verify this by setting a breakpoint in the main loop. The watchdog itself behaves as it should (in the way you have configured it).

RE: Watchdog timer unexpected Reset in nrf52810

Dilip.n — Tue, 21 Jan 2020 07:20:53 GMT

Hello,

I am feeding the watchdog in main loop

main()

{

NRF_WDT->CONFIG = (WDT_CONFIG_HALT_Pause << WDT_CONFIG_HALT_Pos) | ( WDT_CONFIG_SLEEP_Pause << WDT_CONFIG_SLEEP_Pos);
NRF_WDT->CRV = 1*32768; // 1 sec. timeout
NRF_WDT->TASKS_START = 1

while(1)
{

NRF_WDT->RR[0] = WDT_RR_RR_Reload; //Reload watchdog register 0.
ble_functions();

Uarte_functions();
sd_app_evt_wait();
}

}

Unless there are any interrupts from BLE or UART the device stays in sleep mode and also there in no unexpected reset from watchdog as the watchdog is configured to pause in sleep mode.

Suppose there is an idle connection then there is a reset due to watchdog after 3.5 minutes.

Is there a difference in "sleep mode" for ble active and ble inactive? does watchdog run if there is a idle BLE connection?

RE: Watchdog timer unexpected Reset in nrf52810

Einar Thorsrud — Mon, 20 Jan 2020 12:29:52 GMT

Hi,

There has to be something with the flow of your application that prevents you from feeding/reloading the WDT often enough.

Observations:

You pause the WDT when in sleep.
Reset after 3.5 min when timeout is set to 1 second, and double to 7 minutes when timeout is set to 2 seconds.

I suspect that the WDT is never reloaded. If this is the case, you should see it reset after 1 or 2 seconds respectively if you replace WDT_CONFIG_SLEEP_Pause with WDT_CONFIG_SLEEP_Run. So to fix this, make sure you feed the watchdog regularly.