When using the FatFs module's f_getfree to retrieve the remaining capacity, the correct value cannot be obtained immediately after mounting.

[kkuma256]

I am trying to retrieve the remaining capacity using the f_getfree function in the FatFs module, but I cannot get the correct value immediately after calling f_mount. After using the system for a while, it eventually becomes possible to retrieve the correct value at some point.

Here are my questions:

(1) Since I assume the FAT should be in a clean state immediately after mounting, why can't I get the correct value right away?
(2) What should I do to ensure the correct value is retrieved?

[Hung Bui]

Hi Koji, 

Please show your code.

Also please verify the SPI communication using a logic analyzer.