Storing Persistent User information in Flash in a Mesh device

[EAn]

Greetings to my fellow NDZ colleagues,

We have developed an ecosystem of devices which operate in a sensor network in BT Mesh. We are using nRF52840 and our code-base is nRF5 SDK 16.0.0 and nrf5 SDK for Mesh v4.2.0.

Certain devices need to store persistent calibration data, which must be kept even after updating the firmware via DFUOTA.
Right now we get this information via Mesh and write it to the customer[0-31]  entries of the UICR. The issue emerges when we want to write a new set of calibration constants:

a) If we want to do corrections to the calibration and overwrite this information, we need to erase and rewrite the UICR, I have tried that to no avail, I can not erase and write again from the application. Is it possible to re-write the UICR from the application?

or (and this would perhaps be preferable)

b) Is there an area of the Flash memory which we would use to store such persistent app data that would survive DFUOTA, without having to reprogram and rebuild the bootloader?

c) Anyone has any other idea?


Thank you so much!

Regards,

//EA

[Mttrinh]

Hi,

We will highly recommend you to move to nRF5 SDK for Mesh v5.0.0, and use "mesh_config" module to store the special data. This data can be preserved across the DFU cycles as long as they do not change number and format of defined mesh config data entries.

EDIT: You can find more documentation regarding the module here.

There have been many bug fixes and improvements in the latest SDK version. We fixed one important mesh_config issue and several other issues as well. See release notes.

[Mttrinh]

Have a look at my edit in my first post on usage of the module.

[EAn]

Thanks you Mttrinh. You've been very helpful. One of our developers already used mesh_config so it should be easy to get to where we need to go. Thank you for the pointer.

However, I am curious about the answer to my other part of the question: "Is it possible to re-write the UICR from the application?" , for an nRF52840. Thank you! 

[Mttrinh]

Hi,

EAn said:

However, I am curious about the answer to my other part of the question: "Is it possible to re-write the UICR from the application?" , for an nRF52840

You can read more about that here.