Can DFU BLE service be used for data (not application) update?

[yes]

Our products are based on nRF52832 & nRF52840 and include display.

We use DFU mechanism for application update.

According to Nordic's documentation DFU supports multi-application i.e. more than one application on flash memory.

Can we use the DFU service for updating separated data (non-application) sectors e.g. change languages files without updating application?

Thanks in advance 

[Hung Bui]

Hi Yerry, 

We do have an option to update only the application and leaving the application data intact. You can read about that here. 

However, if you want to update only the data but not the application, it could be a little bit more complicated. 

We until lately doesn't support this option yet. And the easiest way was to modify the bootloader to have one extra DFU option (beside application, softdevice, bootloader) to do data update. 

In SDK 15.3 we have a new feature that mentioned in the release note here: 

Added the option to send applications that will not be activated, but will remain in slot 1 ("external applications"). This functionality requires nrfutil version 5.0.0 or higher.

Meaning it's possible to not activate the new image and leave it at bank 1. You then in your application can decide what to do with the image/data. How to generate a package for it is mentioned in the pc-nrfutil documentation at Note 3 here.

Update packages of external applications, e.g. updates that are intended for a third party, can be generated by setting the --external-app option. When this option is set the receiving device will store the received update, but not activate it. Note: This functionality is experimental in the nRF5 SDK and not yet used in any examples.