fat32 library FILE_APPEND question

[Karamel]

Hi,

I would like to make data logger with this library. I tried something about file append but any code didn't work. I have a txt file which name is R.TXT and I call these code every 1 second. I would like to add someting below my txt file but they do not work.

Code: Select all

fileHandle[0] = FAT32_Open("R.TXT", FILE_APPEND);
err = FAT32_Write(fileHandle[0], "x", 1);

how can i do this?

Best Regards,
Karamel

[Karamel]

Is there anyone who can tell it me?

[aleksa.jovanovic]

Have you tried without "err=" ?
Just "FAT32_Write(fileHandle[0], "x", 1);" ?

Also did you initialize FAT32?

Best regards,
Aleksa

[Dany]

I have a txt file which name is R.TXT and I call these code every 1 second. I would like to add someting below my txt file but they do not work.

Code: Select all

fileHandle[0] = FAT32_Open("R.TXT", FILE_APPEND);
err = FAT32_Write(fileHandle[0], "x", 1);

If you call this code every second then you also have to close the file every time, because you (re)open it each second also. Not closing the file can lead to loss of data (as you see happening).
The alternative is opening the fille for appending once, write many times 'X', and close the file once. Failing to close the file can lead to loss of data of course (closing the file updates the FAT for sure).

[Karamel]

Have you tried without "err=" ?
Just "FAT32_Write(fileHandle[0], "x", 1);" ?

Also did you initialize FAT32?

Best regards,
Aleksa

Hi,

Yes I have initialized FAT32. Actually, my problem is that.

default size of my txt file is four. What is the meaning that? for example, "mikr".

when I want to write in side "amazing". it writes but like that "amaz"

when I write my txt file "abcdefg" with my computer and then, microcontroller can write inside "amazing".

library can not append any text to my txt file
it just can change string in txt file

[aleksa.jovanovic]

Could you post the project so I can try it out ?

Best regards,
Aleksa

[Karamel]

Hi,

thanks for interesting aleksa.

I have added my simple code. it can write like my previous message and it can not append(add) any string to my txt file.

Best Regards,
Karamel

[Karamel]

I have a txt file which has a 3 letter inside like that. (I had written it with my computer)



and then, I take off my sd card from my computer and I plug it my test board(has stm32f103vet6 microcontroller) it tries to write "amazing" to my tft file.

finally, I take off my card from pcb and I plug it my computer. It looks like that.



microcontroller can not write "amazing" to R.TXT. it just can write 3 letter. Library also can not append any string.

[Dany]

Hi, try to
- use FILE_APPEND in stead of FILE_WRITE
- close the file after writing to it.

[Karamel]

Thank you so much Dany

Now, it works with these codes.

Code: Select all

    err = FAT32_Size("R.TXT", &size);
    FAT32_Seek(fileHandle[0], size);

    FAT32_Write(fileHandle[0], "amazing", 10);
    FAT32_Close(fileHandle[0]);

I would like to do new line before writing "amazing" Such as like that.

amazing
amazing
amazing
.
.
.
.

I tried this FAT32_Write(fileHandle[0], "\namazing", 10); but it didn't work. how can I do it?