External SPI Flash Memory + File System + NRF 52832

[Prasad A]

Hi,

I am trying to implement a lightweight file system in my external flash memory (ISSI). After the implementation of file system, I want to store a .bin file and later access the file through c program. I am a beginner in nrf52 board and need some assistance in understanding the implementation method for the above.

1. I need some direction for implementing file system in nrf52832. I am using the following Software/Hardware tools:

• nRF52832
• NRF CONNECT SDK 2.5.1
• SPI FLash Memory: IS25LP128-JBLE
• vscode
• Windows 11 64 bits

       2. I would also like to if I can implement FATFS on the SPI flash memory using the nrf 52832. Is there a link for the lastest version of FAT FS code.

       3. I need some help in understanding if I can use supported files from nrf SDK v 2.5.1 for nrf52832 board? IS there some alteration needed before I upload them to my nrf 52832 board.

Best,

AP

[Shahin97]

Theses zephyr examples may be of some use to you - 

https://github.com/zephyrproject-rtos/zephyr/tree/main/samples/subsys/fs

[Prasad A]

Will this work for nrf 52832 board?

As I have gone through the document and for external flash : "This type of configuration requires external flash device to be available on DK board. Currently following boards support the configuration: nrf52840dk_nrf52840 by nrf52840dk_nrf52840_qspi configuration." . SInce I have a nrf 52832dk board it does not support this board right?

[Shahin97]

QSPI is not supported on the nrf52832, I would start by creating an overlay/device tree entry for regular SPI flash chip and the littlefs example will work. I have not tried the other examples, but can't imagine why they would not work as long as the device tree is correct for spi flash

[Prasad A]

Got it! QSPI could be corrected using the overlay file.

1. What about the board configuration: it states that it supports nrf 52840dk but I am using a nRF52832dk. Will it cause any debug error?

2. Littlefs? I was looking into implementing FATFS for the spi flash memeory

[Shahin97]

There will be no issues with the nrf52832 as long as the dtsi & dts is setup correctly for spi flash & partitions are set up. 

Once this is set up- I would load the example and see if it running correctly. If it is, the device tree entry is working fine, if not the issue will be with the device tree. 

Once the device tree is confirmed to be correct, I would then move on to FATFS. I have not personally used FATFS before so I cannot comment on that

[Shahin97]

The fs_sample has mentions of FATFS so that would be your next step to look into

[Prasad A]

Thank you for the details. I will try to implement the littlefs on the flash memory using the correct dts file description for nrf52832. 

I will later check the same for fs_sample to implement FATFS, if it will work.

I would really appreciate if you know anything about storing a ".bin" file later on this filesystem and being able access this file to edit using the littlefs system ? I do not know much of the capabilities of littlefs over FATFS for such application.