matter NVS settings

[wesson]

I'm using ncs2.6.0 to develop a door lock project for matter, and I'm running into a problem: I need to store some user-set parameters in the project, which take up less space but change frequently, so I'm storing them in settings. But matter itself uses this area for storing information, and it erases my parameter information when matter resumes initialization. How can I separate the storage that comes with matter from my own settings storage?

[Charlie]

Hi Wesson,

Sorry for the late reply. We are short of staff due to summer vacation period.

Settings API (nordicsemi.com) is a Zephyr sample to demonstrate how to use a NVS region to load and save settings using Zephyr setting API library. You can refer to this sample for your own setting storage.

Best regards,

charlie

[wesson]

Yes, I know how to use the setting interface to save data, but I don't know how to assign settings to a custom flash area.

[Charlie]

Hi Wesson,

I just figure out that Zephyr settings subsystem only support a signal instance with one backend, so it is not easy to add a second setting storage for your custom parameters. If you do not like to manipulate NVS directly, could disabling reset erase be an option? 

The CONFIG_CHIP_FACTORY_RESET_ERASE_NVS Kconfig option is set to y by default. To disable removing application-specific non-volatile data when the CONFIG_CHIP_LAST_FABRIC_REMOVED_ERASE_AND_REBOOT Kconfig option is selected, set the CONFIG_CHIP_FACTORY_RESET_ERASE_NVS Kconfig option to n.

If this does not help, I also run out of idea about this inquiry. 

Best regards,

Charlie

[wesson]

Set CONFIG_CHIP_FACTORY_RESET_ERASE_NVS=n Will it affect matter data management

[Charlie]

No, this does not affect Matter-related setting reset. It is explained on Matter document in the opposite way: https://docs.nordicsemi.com/bundle/ncs-2.6.1/page/matter/nrfconnect_examples_configuration.html#factory_reset_behavior

Factory reset behavior

By default, the factory reset procedure implemented in the Matter stack removes Matter-related settings only. If your application does not depend on any device-lifelong data stored in the non-volatile storage, set the CONFIG_CHIP_FACTORY_RESET_ERASE_NVS option to fully erase the NVS partition at the factory reset. This approach is more robust and regains the original NVS performance in case it has been polluted with unwanted entries.