NRF52840 BLE DFU: Application settings

RE: NRF52840 BLE DFU: Application settings

Chris_Dev — Fri, 27 Sep 2019 04:58:51 GMT

Hi Hung, just wanted to let you know that I tested a DFU with different composition data. The composition data is reset automatically and the device is set to an un-provisioned state. So I believe that this is handled correctly.

RE: NRF52840 BLE DFU: Application settings

Chris_Dev — Tue, 17 Sep 2019 12:06:15 GMT

Hi Hung, awesome!

Thank you so much for reply, you cleared it up well:)

RE: NRF52840 BLE DFU: Application settings

Hung Bui — Tue, 17 Sep 2019 11:56:32 GMT

Hi Chris,

You are correct the bootloader setting contains information about the application. However, it's only for the first time programming the chip. On a DFU update where the application changes, the bootloader should be automatically generate bootloader setting that fit with the new application. Think of generating the bootloader setting manually and flashing it is a way of tricking the bootloader to think that it has just done a normal DFU.

Regarding your question, if you change the composition data, the flash module may not work properly. It's better to erase the data and start fresh. I'm not so sure our current flash library can handle this automatically. Most likely you would need to write the code to detect the flash error and erase the flash in the application code.

RE: NRF52840 BLE DFU: Application settings

Chris_Dev — Tue, 17 Sep 2019 08:24:49 GMT

Hi Hung, yes sorry, I meant the bootloader settings:) I have used this tutorial:

https://github.com/gamnes/nRF52832-buttonless-dfu-development-tutorial

So when you generate the settings, you make use of your application hex file with the following command:

nrfutil settings generate --family NRF52840 --application app.hex --application-version 1 --bootloader-version 1 --bl-settings-version 1 settings.hex

These settings depend on your application right? So if your application changes, this file will change as well? Or am I wrong...

The other thing that I'm thinking about is the provisioning data. So if I want to do a DFU update with the following scenario:

1. Current version: 2 generic on/off server models on 2 different elements

2. New version to update via DFU: 4 generic on/off server models on 4 different elements

In this case I will have to reprovision the device? Am I wrong? How would you specify if the provisioned data on the node under DFU update should erase or keep it's provisioning data? If you would like me to rather open up a new ticket for this I would be happy to do so!

RE: NRF52840 BLE DFU: Application settings

Hung Bui — Tue, 17 Sep 2019 08:11:59 GMT

Hi Chris,

Could you clarify what exactly you meant by "application setting" ?

Did you mean "bootloader setting"? If you did then it shouldn't be included in the DFU package.