using sd card without using FAT

[bagavathi]

Hi friends,

without using FAT can we access the memory for store the data like eeprom?

 

[memarian]

Yes,

You can access the SD Card via SPI without using any file system.

 

[tantalos]

Yes, its like a flash memory, but you need to read and write them sector-wise , that is when the sector size is 512 bytes then you need to read and write always blocks of 512 bytes.

 

[bagavathi]

then what is the need of file system . where it is used and which is the best

 

[milan.rajik]

To create and store files.

 

[pisoiu]

Using a file system will allow you to insert that card in any windows/linux/android/mac machine and to read/write files, directories aso. Writing raw data, without a file system will make that card usable only for an application which reads raw data from the card and that application must know what and where it is written.
I had few years ago a device which stored all data from a CAN bus onto a sd card in raw format. Then I placed the card in a PC and with an application which works directly with the card (such as hex workshop) I was able to read data from it. But the PC won't see such a card as a valid drive.