nRF5 SDK System power off MODE wake up issue.

[Theja]

Hi,

I'm working on an application where the system should enter System OFF mode after some button activity and wake up (restart) on a button press or USB connection.

When I flash the application using Segger Embedded Studio, it works as expected. However, when I flash the combined HEX file (containing the bootloader, application, and SoftDevice) generated using the post-build commands, it only wakes up from the button press. If I connect the USB while in System OFF mode, it enters an unknown state where nothing functions.

I compared the HEX files — one read back from the device (flashed via IDE) and the other generated through the post-build commands — and found differences.

Here are the post-build commands I'm using:
call nrfutil settings generate --family NRF52840 --application CenSyn_EEG.hex --application-version 1 --bootloader-version 1 --bl-settings-version 2 bootloader_settings.hex
call mergehex --merge bootloader_settings.hex secure_bootloader.hex --output Combined_bootloader.hex
call mergehex --merge s140_nrf52_7.2.0_softdevice.hex Combined_bootloader.hex --output SD_FBL.hex
call mergehex --merge CenSyn_EEG.hex SD_FBL.hex --output Final_Hex.hex
call nrfutil pkg generate --hw-version 52 --application-version 2 --application CenSyn_EEG.hex --sd-req 0x100 --key-file private.key CenSyn_EEG_DFU.zip

How can I resolve this issue? Any insights would be greatly appreciated.

Regards,
Theja.

[Vidar Berg]

Hello Theja,

If I connect the USB while in System OFF mode, it enters an unknown state where nothing functions.

Please run 'nrfjprog --readregs' when the chip is in this state to see if the register readout may reveal what state the device is in.

I compared the HEX files — one read back from the device (flashed via IDE) and the other generated through the post-build commands — and found differences.

Does the application region in flash contain different data when you check the flash contents after using these two different methods?

nrfjprog --memrd 0x0 --n 0x1000000 > memory_content.txt

call nrfutil settings generate --family NRF52840 --application CenSyn_EEG.hex --application-version 1 --bootloader-version 1 --bl-settings-version 2 bootloader_settings.hex
call mergehex --merge bootloader_settings.hex secure_bootloader.hex --output Combined_bootloader.hex
call mergehex --merge s140_nrf52_7.2.0_softdevice.hex Combined_bootloader.hex --output SD_FBL.hex
call mergehex --merge CenSyn_EEG.hex SD_FBL.hex --output Final_Hex.hex
call nrfutil pkg generate --hw-version 52 --application-version 2 --application CenSyn_EEG.hex --sd-req 0x100 --key-file private.key CenSyn_EEG_DFU.zip

Is there a flash command that comes after this?

Thanks,

Vidar