WDT/OTA Bootloader

[SKo]

Hi,

I´m using a watchdog in my Application. Furthermore I need the ability to use the ota/dfu functionality. I trigger the bootloader with a simple beacon.

if((memcmp(addr.addr, &adv_data.p_data[9], 6)) == 0)

sd_power_gpregret_clr(0xff);

sd_power_gpregret_set(1);

err_code = sd_power_gpregret_get(&gprepret_value);

sd_nvic_SystemReset();

This is my init for the watchdog:

// Configure WDT.

nrf_drv_wdt_config_t config = NRF_DRV_WDT_DEAFULT_CONFIG;

nrf_drv_wdt_init(&config, 0);

nrf_drv_wdt_channel_alloc(&m_channel_id);

nrf_drv_wdt_enable();

this is the feed:

nrf_drv_wdt_channel_feed(m_channel_id);

Probably you know which issue I´m facing. I can´t feed the watchdog while my device is in the bootloader. I was able to debug, so I can say the Watchdog is running while am device is in the bootloader.

I tried to feed the wdt in wait_for_events:

static void wait_for_events(void)

{

for (;;)

{

nrf_drv_wdt_feed();

    // Wait in low power state for any events.

    uint32_t err_code = sd_app_evt_wait();

    APP_ERROR_CHECK(err_code);

    // Event received. Process it from the scheduler.

    app_sched_execute();

nrf_drv_wdt_feed();

    if ((m_update_status == BOOTLOADER_COMPLETE) ||
        (m_update_status == BOOTLOADER_TIMEOUT)  ||
        (m_update_status == BOOTLOADER_RESET))

    {

        // When update has completed or a timeout/reset occured we will return.

        return;

    }

}

}

Perhaps someone has a solution for me. I read this post, but it doesn´t helped me.

devzone.nordicsemi.com/.../

[Maulik Patel]

Hi SKo,

Can you make sure that your application does not go into sleep in function sd_app_evt_wait(). I mean if there is no any event from SD up to Watch Dog Timeout then your chip will cause a Watch Dog Reset. What you can try is, create and add a dummy timer which is in repeated mode and keep expiring every second or so, which will help your bootloader in exiting from sd_app_evt_wait() function and reloading a watchdog timer and then again go into sleep if no activity is there.

I hope this helps you.

Regards, Maulik Patel

[SKo]

I noticed a reset while debugging the bootloader. The WDT RUNNSTATUS Register changed from 1 running, to 0 not running. I think this reset is caused by the wdt?

[Vidar Berg]

The problem is that there are no events during advertisement. Thus, WDT is not being fed in time as @Maulik Patel mentioned.

Another solution to creating an app timer instance is to lower the APP_ADV_TIMEOUT_IN_SECONDS which which will result in BLE_GAP_EVT_TIMEOUT every time the advertisement times out. Program execution will return to the endless loop once the event has been serviced and reload the timer. Note that advertising is restarted in this event, so it will never really time out.