watchdog timer

RE: watchdog timer

Stefan Birnir Sverrisson — Tue, 02 Dec 2014 13:09:10 GMT

There are watchdog examples here for the nRF51

RE: watchdog timer

Bastiaan — Fri, 25 Oct 2013 16:10:39 GMT

Being new at this... We're attempting to use the WDT w/ nrf_wait_for_app_event to pause execution of loop.

Is there a better mechanism to let the CPU/PPI power relax & time the loop? What is it? Examples?

Thank you!

RE: watchdog timer

Guest — Fri, 25 Oct 2013 16:10:39 GMT

Being new at this... We're attempting to use the WDT w/ nrf_wait_for_app_event to pause execution of loop.

Is there a better mechanism to let the CPU/PPI power relax & time the loop? What is it? Examples?

Thank you!

RE: watchdog timer

Gil dePaula — Wed, 28 Aug 2013 23:00:42 GMT

Another update: It is going to the WDT_IRQHandler() ISR as intended. I couldn't tell earlier because it's only there for 2 clock cycles (of the 32 kHz clock - 60 us) before it finally resets. So, it works!!!

RE: watchdog timer

Guest — Tue, 27 Aug 2013 16:21:07 GMT

An update: It now resets. I'm going into sleep mode, so I had to change WDT_CONFIG_SLEEP_Pause to WDT_CONFIG_SLEEP_Run.

But it still does not go to the WDT_IRQHandler() ISR. So I'm guessing the problem is in the INTENSET and NVIC instructions.

RE: watchdog timer

Bastiaan — Tue, 27 Aug 2013 16:21:07 GMT

An update: It now resets. I'm going into sleep mode, so I had to change WDT_CONFIG_SLEEP_Pause to WDT_CONFIG_SLEEP_Run.

But it still does not go to the WDT_IRQHandler() ISR. So I'm guessing the problem is in the INTENSET and NVIC instructions.

RE: watchdog timer

Bastiaan — Tue, 27 Aug 2013 15:57:02 GMT

Thank you Sébastien, Unfortunately it still does not work. I tried it with this: NVIC_SetPriority(WDT_IRQn, APP_IRQ_PRIORITY_LOW); Regards, Gil

RE: watchdog timer

Guest — Tue, 27 Aug 2013 15:57:02 GMT

Thank you Sébastien, Unfortunately it still does not work. I tried it with this: NVIC_SetPriority(WDT_IRQn, APP_IRQ_PRIORITY_LOW); Regards, Gil

RE: watchdog timer

Sébastien Despont — Tue, 27 Aug 2013 15:32:46 GMT

Hi,

If you are using the soft device, you cannot set the priority level as high which is reserved in this case. Try to set it to low priority.

RE: watchdog timer

Gil DePaula — Tue, 27 Aug 2013 14:39:26 GMT

Hi Ole,

I tried the code below, but it doesn't work. It does not go to the handler, and it doesn't reset either. I closed the debugger and did a power cycle as required. In the handler, all I do is turn the LED on (LED function works with a button press, for example). I'm not reloading it anywhere yet either. What am I doing wrong?

void watchdog_init(void) { NRF_WDT->CONFIG = (WDT_CONFIG_HALT_Pause << WDT_CONFIG_HALT_Pos) | (WDT_CONFIG_SLEEP_Pause << WDT_CONFIG_SLEEP_Pos);

NRF_WDT->CRV = (32768 * 1); // Timeout period of 1 s

NRF_WDT->RREN |= WDT_RREN_RR0_Msk; //Enable reload register 0

NRF_WDT->INTENSET = WDT_INTENSET_TIMEOUT_Msk;

NVIC_ClearPendingIRQ(WDT_IRQn); NVIC_SetPriority(WDT_IRQn, APP_IRQ_PRIORITY_HIGH); NVIC_EnableIRQ(WDT_IRQn);

NRF_WDT->TASKS_START = 1; // Watchdog start }

Thank you!

Gil

RE: watchdog timer

Hans-Christian Otto — Tue, 27 Aug 2013 07:49:17 GMT

Ah now it works, the problem was: At the beginning I set the 3V_enable_switch to on. After the WDT reset+pull down the 3V_enable_switch the uC reset very fast and have enough power to reach the row with the 3V_enable_switch command.

RE: watchdog timer

Hans-Christian Otto — Tue, 27 Aug 2013 07:40:00 GMT

Sorry but this doesnt work, too. I use this steps:

lfclk_config(); CRV = (32768) - 1;
NRF_WDT->RREN = (WDT_RREN_RR0_Enabled INTENSET = 1;
NVIC_EnableIRQ(WDT_IRQn);
NVIC_SetPriority(WDT_IRQn,0);

in the ISR I pull down the enable pin from my 3V LDO to power off the uC.

RE: watchdog timer

Ole Morten — Tue, 27 Aug 2013 06:56:59 GMT

This would probably have been better as a separate question. :-)

A quick guess is however that you haven't done a pin reset after enabling the watchdog. The watchdog doesn't run as long as the debugger is enabled, and the debug interface stays enabled till a power-cycle or a pin-reset (which can be done with for example nrfjprog -p).

RE: watchdog timer

Hans-Christian Otto — Tue, 27 Aug 2013 06:53:22 GMT

The watchdog timer doesnt work on my nrf51822! I set the timer and started as in the example just like that but thje system doesnt reset or do a interrupt (for ISR i enable the interrupt).

I also use the RTC for a simple timer in my system and use as source the RC.

RE: watchdog timer

Ole Morten — Fri, 16 Aug 2013 12:05:48 GMT

If you want to use the watchdog interrupt, this is used like any other interrupt, you enable the event to generate an interrupt in the peripheral's INTEN register, and then enable the interrupt in the NVIC.

As you can see in section 19.1.3 of the reference manual, this will give you 2 32.768 kHz clock cycles to do your logging and stack tracing. On reset, you can use the RESETREAS register to know the cause of the reset.

The name of all interrupts are most easy to find in the startup file, and as you can see there, the watchdog interrupt handler will by default be WDT_IRQHandler. There are no utilities available to do stack tracing, but you can take a look at the ble_debug_assert_handler() function, which does similar things.

RE: watchdog timer

Bret Foreman — Tue, 13 Aug 2013 13:56:13 GMT

The attached file does show some of the basics but not much. I took a look at nrf51.h where the data structures are defined and the comments are pretty terse there too. I want to make sure I use this timer correctly in the context of a device that sleeps, wakes on one of a number of interrupt signals, does some processing, and goes back to sleep. Should the processing hang, I'd like the watchdog to interrupt the MCU, for the watchdog handler to log a message and a stack trace to flash, and then do a reset. I would expect that everyone would want to do this for production code and I'm surprised I couldn't find an example or at least more documentation.

For example, what is the name of the watchdog interrupt handler and what utilities exist to log a stack trace?

RE: watchdog timer

Ole Morten — Tue, 13 Aug 2013 09:31:25 GMT

Please take a look at the main-file that should show the basics.

main.c