Using the DFU SDK 12.1 with a BLE command to jump to 'bootloader' works every other time with nordic connect app

[sananth]

We have been using the DFU that came with the sdk 12.1 with a modification (essentially removing the button from the DFU code). We currently send an application command that will tell the code to 'jump' to the bootloader. This works great. Once the app command is reeived the device begins advertising 'DFUTarg' I use the nrf connect android app to load the .zip file.

It works the first time, and every odd number time after; hence the second time of jumping back to the bootloader it will appear as if the app was loaded properly and nrf conenct will state the app was successfully loaded but when I scan the device still advertises as DFUTarg. If I try to load again, it will say successfully loaded and will advertise with our custom name.

We have the watchdog timer enabled in the application and following some other posts I added NRF_WDT->RR[0] = WDT_RR_RR_Reload; to the wait_for_event loop in the DFU to pet the dog.

Any suggestions?

[sananth]

Hi Bjorn,

We start/setup the watchdog right before we enter the

for (;;)
{
    app_sched_execute();
    UTIL_kickWatchdog();
    APP_ERROR_CHECK(sd_app_evt_wait());
}

It is hard to pinpoint when the failure occurs. We currently have an led that is one during the bootloader phase. It most likely is happening at the end of the bootloading (or at least that is my guess). As when it works the led blinks really quickly and shuts off. Versus when it doesn't work the led goes off and within a second is back on. All signs on the nordic phone app make it seem like it correctly boot loaded.

Do you have an suggestions on what to try to debug this better? So I can provide more info