nRF52840 SDK16 - USB MSC example - How to check if FAT volume exists

RE: nRF52840 SDK16 - USB MSC example - How to check if FAT volume exists

Nikosant03 — Mon, 18 Jan 2021 14:29:13 GMT

Thank you for your fast support Jorgen!!

RE: nRF52840 SDK16 - USB MSC example - How to check if FAT volume exists

Jørgen Holmefjord — Mon, 18 Jan 2021 14:20:34 GMT

[quote user="Nikosant03"]Everytime the system reset/restart I have to call the f_mount() function?[/quote]

Yes, if you want to perform any file/directory operations. From the description of the function: "Prior to perform any file/directory operations, a filesystem object needs to be registered with f_mount function for the logical drive."

[quote user="Nikosant03"]what if the disk is already be mounted and I call f_mount() again? Is it safe? Re-mount the default drive will reinitialize the filesystem.. Could this lead to data loss?[/quote]

That should be fine, it will just re-init the filesystem object (FATFS* fs). However, note the following line from the description: "If there is any open object of file or directory on the logical drive, the object will be invalidated by this function."

RE: nRF52840 SDK16 - USB MSC example - How to check if FAT volume exists

Nikosant03 — Mon, 18 Jan 2021 14:03:52 GMT

Hi Jorsen and thank you for your answer

Everytime the system reset/restart I have to call the f_mount() function? I mean, what if the disk is already be mounted and I call f_mount() again? Is it safe? Re-mount the default drive will reinitialize the filesystem.. Could this lead to data loss?

This is the first time I come across with file systems so excuse my ignorance 🙂

Nick

RE: nRF52840 SDK16 - USB MSC example - How to check if FAT volume exists

Jørgen Holmefjord — Mon, 18 Jan 2021 13:36:40 GMT

Hi,

f_mount() should return FR_NO_FILESYSTEM if there is no FAT file system present on the logical drive.

Best regards,
Jørgen