Bootloader doesn't load application on power-on

[dingari]

I have a small problem with my bootloader + application on NRF52832. I'm using SDK 12.2.0 with S132 v3.0.0.

When the device loses power, and power is then re-applied, the bootloader doesn't start the application. If I however issue a reset through SWD, the application is started.

Everything else is working as expected (BLE DFU firmware update etc.). I know there isn't a lot to go on, but I'm hoping there is a simple explanation.

[Hung Bui]

Hi,

How does the application start at the first place? I assume it only start on the first run if you do DFU update but not if you do a power rest after that ?

When the bootloader didn't start application what did it do ?Would it advertise as DFUTarg ? Or it's simply bricked ?

You may want to check what happened inside the bootloader, simply debug it, add a breakpoint in main and step the code (you may need to put optimization level to 0 )

[dingari]

Hi, the device starts in the bootloader advertising as DFUTARG. There are two ways I can get it out of bootloader mode: Do a DFU update or issue a reset through SWD.

[Hung Bui]

Please give information on this:

When the bootloader didn't start application what did it do ?Would it advertise as DFUTarg ? Or it's simply bricked ?

Have you tried to debug the bootloader ?

[dingari]

Hi, I said before that the bootloader starts advertising as DFUTARG.

I haven't had the chance to debug the bootloader yet.

[Hung Bui]

If it advertise as DFUTarg and doesn't enter your application, meaning it thinks that the application is not valid. This could be due to CRC mismatch.

Do you do any flash operation in your application ?

Please step into bootloader code and check the return value of nrf_dfu_app_is_valid() inside nrf_dfu_init().

Could you test doing DFU with any of our example for example the ble_app_hrs .