Watchdog event handler isn't called

[snowuyl]

I try to simulate system hang by adding while(1) after calling watch dog feeding function. But watchdog event handler _wdtEventHandler() isn't called.

int main(void) {

    ...

    wdtInit();

    for (;;) {
        wdtFeed();
        while(1);

}

[snowuyl]

wdt.h

Fullscreen 0486.wdt.c Download

#include "error.h"
#include "nrf_log.h"
#include "nrfx_wdt.h"
#include "wdt.h"

static bool _gWdtInitialized = false;
static nrfx_wdt_channel_id _gWdtChannelID;

void _wdtReboot(void) {
    NVIC_SystemReset();
}

/*
 *  WDT events handler.
 */
static void _wdtEventHandler(void) {
    NRF_LOG_WARNING("Watchdog timer event handler\n");
    //_wdtReboot();
}

int wdtInit(void) {
    ret_code_t errCode;
    nrfx_wdt_config_t wdtConfig = NRFX_WDT_DEAFULT_CONFIG;
	errCode = nrfx_wdt_init(&wdtConfig, _wdtEventHandler);
    if (errCode != NRF_SUCCESS) {
	    NRF_LOG_WARNING("nrfx_wdt_init() failed\n");
        return ERROR_WDT_INITIALIZE_FAIL;
    }
    
	errCode = nrfx_wdt_channel_alloc(&_gWdtChannelID);
	if (errCode != NRF_SUCCESS) {
	    NRF_LOG_WARNING("nrfx_wdt_init() failed\n");
        return ERROR_WDT_INITIALIZE_FAIL;
    }

	nrfx_wdt_enable();

    _gWdtInitialized = true;

    return 0;
}

int wdtFeed(void) {
    if (!_gWdtInitialized) {
        return ERROR_WDT_UNINITIALIZED;
    }

    NRF_LOG_DEBUG("Watchdog timer feed\n");
    nrfx_wdt_channel_feed(_gWdtChannelID);

    return 0;
}



//void WDT_IRQHandler(void) {
//    NRF_LOG_WARNING("Watchdog timer interrupt handler\n");
//}

[snowuyl]

From the following log messages, nrfx_wdt_init() and nrfx_wdt_channel_alloc return NRF_SUCCESS. But why Watchdog event handler isn't called?

# SEGGER J-Link RTT Viewer V6.32i Terminal Log File
# Compiled: 15:22:50 on Jul 24 2018
# Logging started @ 04 Jul 2022 13:55:29
 0> <info> PRS: Function: nrfx_prs_acquire, error code: NRF_SUCCESS.
 0> <warning> UARTE: Function: nrfx_uarte_init, error code: NRF_SUCCESS.
 0> <info> UARTE: Transfer rx_len: 1.
 0> <info> UARTE: Function: nrfx_uarte_rx, error code: NRF_SUCCESS.
 0> <info> app: ========| flash info |========
 0> <info> app: erase unit:   4096 bytes
 0> <info> app: program unit: 4 bytes
 0> <info> app: end address: 0x7FFFF
 0> <info> app: ==============================
 0> <info> SAADC: Function: nrfx_saadc_init, error code: NRF_SUCCESS.
 0> <info> PRS: Function: nrfx_prs_acquire, error code: NRF_SUCCESS.
 0> <warning> UARTE: Function: nrfx_uarte_init, error code: NRF_SUCCESS.
 0> <info> UARTE: Transfer rx_len: 1.
 0> <info> UARTE: Function: nrfx_uarte_rx, error code: NRF_SUCCESS.
 0> <info> app: ========| flash info |========
 0> <info> app: erase unit:   4096 bytes
 0> <info> app: program unit: 4 bytes
 0> <info> app: end address: 0x7FFFF
 0> <info> app: ==============================
 0> <info> SAADC: Function: nrfx_saadc_init, error code: NRF_SUCCESS.
 0> <info> SAADC: Function: nrfx_saadc_channel_init, error code: NRF_SUCCESS.
 0> <info> SAADC: Function: nrfx_saadc_buffer_convert, buffer length: 1, active channels: 1.
 0> <info> SAADC: Function: nrfx_saadc_buffer_convert, error code: NRF_SUCCESS.
 0> SS.
 0> <debug> SAADC: Event: NRF_SAADC_EVENT_END.
 0> <info> app_timer: RTC: initialized.
 0> <info> CLOCK: Function: nrfx_clock_init, error code: NRF_SUCCESS.
 0> <debug> app: NOR_DATA_PERIOD=819
 0>
 0> <debug> app: NOR_RECORD_PERIOD=8192
 0>
 0> <info> WDT: Function: nrfx_wdt_init, error code: NRF_SUCCESS.
 0> <info> WDT: Function: nrfx_wdt_channel_alloc, error code: NRF_SUCCESS.
 0> <info> WDT: Enabled.
 0> <debug> app: Watchdog timer feed
 0>
 0> <error> app: ERROR 4 [NRF_ERROR_NO_MEM] at ..\..\..\..\..\..\com<error> app: End of error report

[Vidar Berg]

Hello,

It sounds like it is working now, but that you are just missing some log messages at the beginning of main()?

[snowuyl]

Watch dog event handler is working now. But soft reset can't trigger to run main() again.

[Vidar Berg]

How do you determine that the program is not reaching main() after the reset? Are you sure it's not just that some log messages are being lost?

Also,  _wdtReboot(); could have been replaced with a while(1) as the WD will trigger a reset after the timeout event.

[snowuyl]

I have added turning on LED in main(). But LED isn't turning on after soft reset.

[Vidar Berg]

It doesn't make sense why the program would not reach main following a reset. Can you place a breakpoint in main and see if it is reached after the reset, and if not, halt the CPU and see where the program actually hangs?