Dude with Mmc_Fat_Library mikroC

[juliozv]

Hi,

I make a datalogger project, I use sensors like temperature, humidity and RTC, but I need to add the SD Card for keep the information. when I read the Mmc_Fat library of mikroC PRO but I don't understand well the next routine:

Mmc_Fat_Assing( filename , file_cre_attr)

* mikroC say
  file_cre_attr: file creation and attributs flags. Each bit corresponds to the appropriate file attribut:

Bit   Mask     Description

0   0x01     Read Only
1   0x02     Hidden
2   0x04     System
3   0x08     Volume Label
4   0x10      Subdirectory
5   0x20     Archive
6   0x40     Device (internal use only, never found on disk)
7   0x80     File creation flag. If file does not exist and this flag is set, a new file with specified name will be created.

in the part the "file_cre_attr" how is the configuraion of bits? in the example of mikroE has 0xA0 but I don't understand where this value.

thanks for your time..

[bigtoy]

Hex 0xA0 is Binary 10100000, so bits 7 and 5 are set. In other words, "create a new file if the specified file name doesn't already exist", and "set the archive bit".  The remaining bits are all clear, so it's not a read-only file, not hidden, not a system file, not a volume label, not a subdirectory, and not a device.

[sam_des]

Hi,

I have never used the mikroC, but I guess you can OR the flags to assign multiple attributes to file.
e.g. 0x01 | 0x02 -> 0x03 -> Read Only + Hidden
      0x80 | 0x10 | 0x04 -> 0x94 -> Create file if doesn't exist, Make it(existing or new) System Subdirectory.

Of course, some of the combinations may be invalid.

It seems mikroC library is FAT16 implementation, you can get lots of info about it on net.

Hope this helps,
sam_des

[pablo2048]

Just look into elm-chan fatfs module (http://elm-chan.org/fsw/ff/00index_e.html) - i suggest to define attributes in this way:

Code:

#define ATTR_READONLY (0x01)
#define ATTR_HIDDEN (0x02)
...

so You can write

Code:

Mmc_Fat_Assing(filename, ATTR_READONLY | ATTR_HIDDEN...)

[juliozv]

 , yes it's a OR function:

In this case file_cre_attr = 0xA0, means Archive and File creation flag,
because, 0xA0 = 0x20 + 0x80 (0x20 -> Archive, 0x80 -> File creation flag).

Just look into elm-chan fatfs module (http://elm-chan.org/fsw/ff/00index_e.html) - i suggest to define attributes in this way:

Code:

#define ATTR_READONLY (0x01)
#define ATTR_HIDDEN (0x02)
...

so You can write

Code:

Mmc_Fat_Assing(filename, ATTR_READONLY | ATTR_HIDDEN...)

it's a good generic FAT file system module and similar of mikroC.