Power off while writing pairing information

RE: Power off while writing pairing information

toshi.g — Mon, 05 Jun 2023 10:30:23 GMT

This answer is fine.
Thank you for your answer.

RE: Power off while writing pairing information

Hung Bui — Mon, 05 Jun 2023 09:19:19 GMT

Hi Toshifumi,

If you are using nRF5 SDK, it's most likely that you use peer_manager module to handle bonding. The peer_manager module uses FDS as the flash backend to handle writing and erasing bond information.
In the documentation for FDS you can find this record format: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/lib_fds_format.html?cp=9_1_3_16_2_0#lib_fds_format_data

So each record would have a record key and CRC. The record key can decide if the data is invalidated or not. And the CRC value will check if the data has been stored properly or not.

So if there is a power shortage when storing or deleting data scenario number 2 will happens.
Only after the records are stored with correct CRC it will be valid. So you don't have to worry about corrupted data when you booting up.

RE: Power off while writing pairing information

toshi.g — Mon, 05 Jun 2023 08:51:10 GMT

Dear Support,

I will write the requested information.

firmware using on the chip ?
　chip:nRF52840
　softdevice:S140_nrf52_7.3.0

Which SDK is used ?
　nRF5_SDK 17.1.0

RE: Power off while writing pairing information

Hung Bui — Mon, 05 Jun 2023 07:39:39 GMT

Hi Toshifumi,

Could you please give us more information about the firmware using on the chip ? Which SDK is used ? Is it nRF Connect SDK or nRF5 SDK ?

In most cases, there will be a flash management that handle the bond information storing and reading. If there is an interruption when storing data the data will not be validated. And the next time when the device turned on it will not read such data.
So in most cases, scenario number 2 will be the case.
Regarding deleting bond, if any part of the data has been deleted but the whole delete has not completed, the data will not be valid in the next boot (because of CRC mismatch) and the data will be considered invalid and device will not load the corrupted bond information.