Fstorage issue without SoftDevice

RE: Fstorage issue without SoftDevice

raphael_gsa — Tue, 05 Mar 2019 12:51:08 GMT

Thanks Einar and awneil,

It is working now thanks to the page erasing before any new writing operation.
Thanks a lot for the very detailed explanations.

RE: Fstorage issue without SoftDevice

awneil — Tue, 05 Mar 2019 12:21:30 GMT

[quote userid="76201" url="~/f/nordic-q-a/44376/fstorage-issue-without-softdevice/174184"]the concerned page must be erased before being written again[/quote]

Yes, that's basically [1] correct.

The ability to update records is one of the things that FDS adds for you:

https://devzone.nordicsemi.com/f/nordic-q-a/44183/including-flash-storage-library-into-another-ble-example/173253#173253

[1] To be more precise, it is a feature of any Flash memory that '1' is the erased state of a bit. You can only write (or "program") bits from a '1' to a '0'; to get from a '0' to a '1' requires an erase operation.

So you can write a page more than once; but you can only change bits from '1' to '0' - any bits that have already been written to '0' cannot be set back to '1' without an erase.

RE: Fstorage issue without SoftDevice

Einar Thorsrud — Tue, 05 Mar 2019 11:31:08 GMT

Hi,

This should be OK, but we have only seen snippets and not the full flow of your application. Can you make a minimal example that demonstrate this issue? If not, an alternative for sharing your code could be to create a private support case and refer to this thread.

RE: Fstorage issue without SoftDevice

raphael_gsa — Tue, 05 Mar 2019 09:17:01 GMT

Hi Einar,

Thanks for your answer, here is the implementation of the vWaitForFlashReady( ) function :

/**
 * @brief Wait for events while flash storage is busy.
 *
 * @param p_fstorage Pointer to the fstorage instance to wait for.
 */
static void vWaitForFlashReady(nrf_fstorage_t const * p_fstorage)
{
    /* While fstorage is busy, sleep and wait for an event. */
    while (nrf_fstorage_is_busy(p_fstorage))
    {
        __WFE();
    }
}

I prefer not to share the entire project at the moment as it is a strategic project for my company. However, after some more research and tests, I found out that when using the NVMC api backend, the concerned page must be erased before being written again. When doing so, it works pretty well. Can you confirm ? If so, is it also needed when using the SD api backend in combination with the SoftDevice ?

Thanks again.

RE: Fstorage issue without SoftDevice

Einar Thorsrud — Tue, 05 Mar 2019 08:59:21 GMT

Hi,

Can you show us the implementation of your vWaitForFlashReady() function? (Or even better, upload your whole project so that I can test on my side). Which SDK are you using?

RE: Fstorage issue without SoftDevice

raphael_gsa — Mon, 04 Mar 2019 15:00:15 GMT

After a lot of identical tries, it sometimes write the data... I don't understand such a weird behavior.