write/read to the flash

RE: write/read to the flash

Edvin — Mon, 01 Jul 2019 13:02:06 GMT

I see that you closed this ticket. Will continue in your new ticket:
https://devzone.nordicsemi.com/f/nordic-q-a/49166/fail-to-using-fds-in-uart-mesh-program

RE: write/read to the flash

awneil — Wed, 26 Jun 2019 12:56:13 GMT

Another issue with using the same address over and over, and just erasing the flash page in between is that you will soon wear out the flash.

This is one of the things that FDS manages for you...

RE: write/read to the flash

Edvin — Wed, 26 Jun 2019 12:52:43 GMT

Do you refer to flash_manager_remove() from the Mesh SDK? It will also remove all the mesh network settings for the device. The issue with using the same address over and over, and just erasing the flash page in between is that if something happens, e.g. you lose power after erasing and before writing, your device may not operate successfully (depends on your application).

If you intend to create a mesh node, I would not recommend using flash_manager_remove to update your flash record.

RE: write/read to the flash

noam — Wed, 26 Jun 2019 12:17:21 GMT

thanks for the help!!!

i now understand my issue.

i success to write,read and update the flash by using the function in the flash_manager.c (the same way in the attached file here).

to erase i'm using flash_manager_remove(flash_manager_t * p_manager);

RE: write/read to the flash

awneil — Wed, 26 Jun 2019 09:14:22 GMT

[quote userid="26071" url="~/f/nordic-q-a/49007/write-read-to-the-flash/194790"]You may not be aware that the flash can only written to once. Then you need to erase entire flash pages before you write to them again[/quote]

Indeed.

noam This applies to any flash - it is not specific to Nordic or nRF52 or ARM Cortex.

See:

https://devzone.nordicsemi.com/f/nordic-q-a/47969/difference-between-fds_record_update-and-fds_record_write/190460#190460

RE: write/read to the flash

Edvin — Wed, 26 Jun 2019 08:29:29 GMT

awneil is right. If you want to store some variables and update them from time to time, I suggest that you look into FDS. You may not be aware that the flash can only written to once. Then you need to erase entire flash pages before you write to them again. This means that you can't just update a specific address any number of times. FDS will handle the placement of the flash records for you.

RE: write/read to the flash

awneil — Wed, 26 Jun 2019 07:52:15 GMT

That does not require it to be at a specific address!

Have you looked at:

Flash Storage:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/lib_fstorage.html

FDS:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/lib_fds.html

RE: write/read to the flash

noam — Wed, 26 Jun 2019 07:50:06 GMT

because its a data that i want to up date and read it every time that the device make restart/power up.

RE: write/read to the flash

awneil — Wed, 26 Jun 2019 07:22:16 GMT

[quote userid="78792" url="~/f/nordic-q-a/49007/write-read-to-the-flash"] i want to write/read user data to/from the flash from specific address [/quote]

Why does it have to be a specific address?

http://www.catb.org/esr/faqs/smart-questions.html#goal