I want to write bonding information in the external area

[sdi_kei]

Hello.
I am developing using nrf52832 (S132 v7.0.1, SDK v16.0.0).

I use whitelist to store bonding information.
This bonding information is written to the flash area using FDS, but I would like to write the bonding information in an external EEPROM or the like.

Is it possible to expand the external EEPROM etc. as an area to write the bonding information, or to duplicate the bonding information in the EEPROM etc.?

I would like to know the materials and methods.

Thank you.

[Hung Bui]

Hi Kei, 

Is the requirement to keep bonding information in external EEPROM a hard requirement ? Could you give more info on why you need to store the data externally ? 
As explained in the other case, you can extend the number of page for FDS (in the internal flash) hence extend the number of bonded peers that you can store. 

FDS doesn't support external flash out of the box. What you need to do is to modify the fstorage backend (fstorage is used by fds) to store the data on external flash instead of internal flash. 

[sdi_kei]

thank you for your answer.

This is because we want to write the bonding information to both the internal flash and the external flash to retain the data.

Is there a sample that writes data to an external flash?

Thank you.

[Hung Bui]

Hi Kei, 

We do have example for writing to external flash (for example the \peripheral\qspi flash example) but it's not combined with fstorage. 
What you would need to do is to study the nrf_fstorage_nvmc.c file where we access the internal flash and convert that into for example nrf_fstorage_spi_eeprom.c so that it access the external EEPROM instead of the internal flash(rewrite the read(), write() functions).