How to enable watchdog

[Francesca]

Hi, I'm a beginner in programming Nordic uC and I would like to know how to enable the watchdog in my application. Are there particular functions to call? Thanks!

[max]

Hi,

This is how i do it

Init

static void System_task_initWatchdog(void)
{
  nrf_drv_wdt_config_t config = NRF_DRV_WDT_DEAFULT_CONFIG;
  uint32_t err_code = nrf_drv_wdt_init(&config,WatchdogHadler);
  APP_ERROR_CHECK(err_code);
  err_code = nrf_drv_wdt_channel_alloc(&m_channel_id);
  APP_ERROR_CHECK(err_code);
  nrf_drv_wdt_enable();
  
}

Feed

nrf_drv_wdt_channel_feed(m_channel_id);

sdk_config.h

#ifndef WDT_ENABLED
#if WDOG
#define WDT_ENABLED 1
#else
#define WDT_ENABLED 0
#endif
#endif
#if  WDT_ENABLED
// <o> WDT_CONFIG_BEHAVIOUR  - WDT behavior in CPU SLEEP or HALT mode

// <1=> Run in SLEEP, Pause in HALT 
// <8=> Pause in SLEEP, Run in HALT 
// <9=> Run in SLEEP and HALT 
// <0=> Pause in SLEEP and HALT 

#ifndef WDT_CONFIG_BEHAVIOUR
#define WDT_CONFIG_BEHAVIOUR 0
#endif

// <o> WDT_CONFIG_RELOAD_VALUE - Reload value  <15-4294967295> 


#ifndef WDT_CONFIG_RELOAD_VALUE
#define WDT_CONFIG_RELOAD_VALUE 20000
#endif

// <o> WDT_CONFIG_IRQ_PRIORITY  - Interrupt priority


// <i> Priorities 0,2 (nRF51) and 0,1,4,5 (nRF52) are reserved for SoftDevice
// <0=> 0 (highest) 
// <1=> 1 
// <2=> 2 
// <3=> 3 
// <4=> 4 
// <5=> 5 
// <6=> 6 
// <7=> 7 

#ifndef WDT_CONFIG_IRQ_PRIORITY
#define WDT_CONFIG_IRQ_PRIORITY 7
#endif

[AmbystomaLabs]

Also since it is not a protected service you can write directly to the registers if you want:

void wdt_init(void)
{
NRF_WDT->CONFIG = (WDT_CONFIG_HALT_Pause << WDT_CONFIG_HALT_Pos) | ( WDT_CONFIG_SLEEP_Run << WDT_CONFIG_SLEEP_Pos);
NRF_WDT->CRV = 150*32768; // 150 sec. timout
NRF_WDT->RREN |= WDT_RREN_RR0_Msk; //Enable reload register 0
NRF_WDT->TASKS_START = 1;
}

//And this bit refreshes the WDT.  Just put it where ever you think is appropriate. 
NRF_WDT->RR[0] = WDT_RR_RR_Reload; //Reload watchdog register 0

[Francesca]

Hi, thanks for your answer! I'm not sure what nrf_drv_wdt_channel_feed(m_channel_id); is useful for and where to place it (maybe in the for(;;)?). Moreover what's the meaning of WDT_CONFIG_RELOAD_VALUE? Thanks!

[max]

feed can be placed in the main loop WDT_CONFIG_RELOAD_VALUE is a time in milliseconds before the WD is accrues. every feed you reload the timer aggain