Softdevice - WDT event not occurring when it hangs

[Neeraj Dhekale]

Hello,

I am using nRF52833 based BE33 (Celium Devices) and using nRF52SDK17.0.2. I am trying to implement WDT and expecting to occur its event when the module becomes hang or any unexpected error occurred. I am purposely written the code where BLE is advertising and after every 1 second I am trying to update BLE advertise data below is the code that does this.

void advertising_update(uint8_t loadcellnumber,uint8_t loadcell_data[])
{
uint32_t err;
  err=  sd_ble_gap_adv_stop(m_advertising.adv_handle);
    APP_ERROR_CHECK(err);
    switch(loadcellnumber){
    case 1:{
      loadcellData[0]=loadcell_data[0];
      loadcellData[1]=loadcell_data[1];
      loadcellData[2]=loadcell_data[2];
      loadcellData[3]=loadcell_data[3];
      break;
      }
    case 2:{
      loadcellData[4]=loadcell_data[0];
      loadcellData[5]=loadcell_data[1];
      loadcellData[6]=loadcell_data[2];
      loadcellData[7]=loadcell_data[3];
      break;
      }
    case 3:{
      loadcellData[8]=loadcell_data[0];
      loadcellData[9]=loadcell_data[1];
      loadcellData[10]=loadcell_data[2];
      loadcellData[11]=loadcell_data[3];
      break;
      }
   }

advertising_init();
advertising_start();
}

WDT code in main.c

#include "nrf_drv_wdt.h"
nrf_drv_wdt_channel_id m_channel_id;

int main(void)
{

//Configure WDT.
    nrf_drv_wdt_config_t config = NRF_DRV_WDT_DEAFULT_CONFIG;
    err_code = nrf_drv_wdt_init(&config, wdt_event_handler);
    APP_ERROR_CHECK(err_code);
    err_code = nrf_drv_wdt_channel_alloc(&m_channel_id);
    APP_ERROR_CHECK(err_code);
    nrf_drv_wdt_enable();
    
    
for (;;)
   {
       idle_state_handle();
       nrf_drv_wdt_feed();
   }
}

I have added below in sdk_config.h file:

// <e> NRFX_WDT_ENABLED - nrfx_wdt - WDT peripheral driver
//==========================================================
#ifndef NRFX_WDT_ENABLED
#define NRFX_WDT_ENABLED 1
#endif
// <o> NRFX_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 NRFX_WDT_CONFIG_BEHAVIOUR
#define NRFX_WDT_CONFIG_BEHAVIOUR 1
#endif

// <o> NRFX_WDT_CONFIG_RELOAD_VALUE - Reload value in ms  <1-131072000> 


#ifndef NRFX_WDT_CONFIG_RELOAD_VALUE
#define NRFX_WDT_CONFIG_RELOAD_VALUE 20000
#endif

// <o> NRFX_WDT_CONFIG_NO_IRQ  - Remove WDT IRQ handling from WDT driver
 
// <0=> Include WDT IRQ handling 
// <1=> Remove WDT IRQ handling 

#ifndef NRFX_WDT_CONFIG_NO_IRQ
#define NRFX_WDT_CONFIG_NO_IRQ 0
#endif

// <o> NRFX_WDT_CONFIG_IRQ_PRIORITY  - Interrupt priority
 
// <0=> 0 (highest) 
// <1=> 1 
// <2=> 2 
// <3=> 3 
// <4=> 4 
// <5=> 5 
// <6=> 6 
// <7=> 7 

#ifndef NRFX_WDT_CONFIG_IRQ_PRIORITY
#define NRFX_WDT_CONFIG_IRQ_PRIORITY 6
#endif

// <e> NRFX_WDT_CONFIG_LOG_ENABLED - Enables logging in the module.
//==========================================================
#ifndef NRFX_WDT_CONFIG_LOG_ENABLED
#define NRFX_WDT_CONFIG_LOG_ENABLED 0
#endif
// <o> NRFX_WDT_CONFIG_LOG_LEVEL  - Default Severity level
 
// <0=> Off 
// <1=> Error 
// <2=> Warning 
// <3=> Info 
// <4=> Debug 

#ifndef NRFX_WDT_CONFIG_LOG_LEVEL
#define NRFX_WDT_CONFIG_LOG_LEVEL 3
#endif

// <o> NRFX_WDT_CONFIG_INFO_COLOR  - ANSI escape code prefix.
 
// <0=> Default 
// <1=> Black 
// <2=> Red 
// <3=> Green 
// <4=> Yellow 
// <5=> Blue 
// <6=> Magenta 
// <7=> Cyan 
// <8=> White 

#ifndef NRFX_WDT_CONFIG_INFO_COLOR
#define NRFX_WDT_CONFIG_INFO_COLOR 0
#endif

// <o> NRFX_WDT_CONFIG_DEBUG_COLOR  - ANSI escape code prefix.
 
// <0=> Default 
// <1=> Black 
// <2=> Red 
// <3=> Green 
// <4=> Yellow 
// <5=> Blue 
// <6=> Magenta 
// <7=> Cyan 
// <8=> White 

#ifndef NRFX_WDT_CONFIG_DEBUG_COLOR
#define NRFX_WDT_CONFIG_DEBUG_COLOR 0
#endif

// </e>

When when I try to connect to BLE from nRF connect App immediately after 1 seconds below error occurs.

<info> app: GATT ATT MTU on connection 0x0 changed to 247.
<error> app: ERROR 8 [NRF_ERROR_INVALID_STATE] at /home/neeraj/Applications/EmbeddedStudio_ARM_Nordic_v568_linux_x64/nRF5SDK1702d674dde/nRF5_SDK_17.0.2_d674dde/examples/peripheral/iotians_device_loadcell/IG_BLE.c:524 (line number 524 is line number 5 in above example)
PC at: 0x0002B885
<error> app: End of error report

Here was I expecting that the WDT event should occur but it was not.

Please help me. Am I expecting wrong? Please correct me if I am wrong.

Thanks and regards,

Neeraj Dhekale

[Simonr]

Oh, right. I didn't catch that. I'm sorry about the misunderstanding. 

The reason you're not seeing the watchdog resetting is because you're feeding it in the main loop. The watchdog won't automatically discovers errors and resets. In release builds, the standard error handler of the SDK will reset handle these kinds of errors by itself and reset. It's recommended you keep that. Then you can use the watchdog to recover from other instances, but then you have to make sure you don't feed the watchdog after something has gone wrong.

Best regards,

Simon

[Neeraj Dhekale]

Thanks simonr,

Thanks for this information.

I was able to make controller restart (it was expected) when there is no any feed for WDT_CONFIG_RELOAD_VALUE 2000 milliseconds but still, WDT event handler wdt_event_handler() function was not getting called.

Thanks and regards,

Neeraj Dhekale