BLE Buttonless DFU App Crashes After Setting High on P0.27 and P1.07 – nRF52840 Custom Board (nRF5 SDK v16 & v17)

RE: BLE Buttonless DFU App Crashes After Setting High on P0.27 and P1.07 – nRF52840 Custom Board (nRF5 SDK v16 & v17)

Hieu — Tue, 22 Apr 2025 13:39:45 GMT

Hi karujoe1406,

[quote user="karujoe1406"]The application itself (without the DFU parts) runs well without issue and have been tested, the problem only comes after the inclusion of the DFU part and secure bootloader. However, if I use secure bootloader and then load the application without the DFU portion, it works well without the option to re-upload a new version of application. [/quote]

I think this is a great hint at where the problem is. What in details is the "DFU portion" that you are referring to here?

RE: BLE Buttonless DFU App Crashes After Setting High on P0.27 and P1.07 – nRF52840 Custom Board (nRF5 SDK v16 & v17)

karujoe1406 — Thu, 17 Apr 2025 02:53:49 GMT

Hi,

Thank you for your reply.

[quote userid="9456" url="~/f/nordic-q-a/120427/ble-buttonless-dfu-app-crashes-after-setting-high-on-p0-27-and-p1-07-nrf52840-custom-board-nrf5-sdk-v16-v17/530675"]Use debug version of the secure bootloader to enable more loggings[/quote]

I have tried with the debug version of the secure bootloader however, the issue was that the debug session crashes right after the application firmware runs. Specifically right when the code executes the (P0.27, P1.07).

[quote userid="9456" url="~/f/nordic-q-a/120427/ble-buttonless-dfu-app-crashes-after-setting-high-on-p0-27-and-p1-07-nrf52840-custom-board-nrf5-sdk-v16-v17/530675"]Test that the application runs alone, without the bootloader[/quote]

The application itself (without the DFU parts) runs well without issue and have been tested, the problem only comes after the inclusion of the DFU part and secure bootloader. However, if I use secure bootloader and then load the application without the DFU portion, it works well without the option to re-upload a new version of application.

[quote userid="9456" url="~/f/nordic-q-a/120427/ble-buttonless-dfu-app-crashes-after-setting-high-on-p0-27-and-p1-07-nrf52840-custom-board-nrf5-sdk-v16-v17/530675"]Test that the application + bootloader setup runs on a reference hardware such as the nRF52840 DK[/quote]

I have tested the application with an NRF52840 DK but the issue would be that the peripheral of the custom board would not be connected. But i will run this test again.

[quote userid="9456" url="~/f/nordic-q-a/120427/ble-buttonless-dfu-app-crashes-after-setting-high-on-p0-27-and-p1-07-nrf52840-custom-board-nrf5-sdk-v16-v17/530675"]Enable immediate log mode instead of deferred log mode.[/quote]

This is currently enabled.

RE: BLE Buttonless DFU App Crashes After Setting High on P0.27 and P1.07 – nRF52840 Custom Board (nRF5 SDK v16 & v17)

Hieu — Fri, 04 Apr 2025 19:55:29 GMT

Hi karujoe1406,

[quote user=""]Are P0.27 or P1.07 used internally or reserved by the secure bootloader or BLE Buttonless DFU app in SDK v16.0.1?[/quote]

No, they are not used or reserved by the secure bootloader or that app.

[quote user=""]Could setting these pins high during application startup affect SoftDevice operation or bootloader-to-app transition?[/quote]

It is not possible to be sure without considering the circuit. What are they connected to on your board?

[quote user=""]Any suggestions for how to further debug the application, especially since I get no logs from it?[/quote]

There are a few things you can try:

Use debug version of the secure bootloader to enable more loggings
Test that the application runs alone, without the bootloader
Test that bootloader runs alone, without the application
Test that the application + bootloader setup runs on a reference hardware such as the nRF52840 DK
Enable immediate log mode instead of deferred log mode. This makes loggings printed out as soon as possible, rather than only pushed periodically.
There is a downside that it can significantly change timing of the firmware, making the test application run significantly different from how it normally does.

Hieu