Does enabling APPROTECT block DFU (BLE update via MCUboot)?

RE: Does enabling APPROTECT block DFU (BLE update via MCUboot)?

Wouter Van Bastelaere — Tue, 21 Oct 2025 12:03:51 GMT

Hi Hung,

thanks for your time.

I’m using nRF Connect SDK version 2.7.0.

At this point, I’m unable to reproduce the issue, either on a minimal setup or on our original configuration where it was first observed.

While it’s a bit concerning that the problem has disappeared, there’s not much I can do without being able to reproduce it.
For now, I’ll consider this issue closed, unless it reappears in the future.

Best regards,
Wouter

RE: Does enabling APPROTECT block DFU (BLE update via MCUboot)?

Hung Bui — Fri, 17 Oct 2025 11:01:29 GMT

Hi Wouter,

I don't see a reason why enable APPROTECT would cause problem with DFU.
When you observed that "The update starts and almost immediately completes, reporting “Success”." did you full erase the chip before flashing the application before DFU ? What can happen is that if the image is already on the secondary slot, it will not be transmitted again.

Could you try to reproduce the issue on a simple smp server sample ? Please check if you can find any log from MCUBoot.
Which SDK version you are on ?