Reading CF card from PIC18F67J50.

[maniac84]

Hi guys,

Recently been given a project of reading files from a CF (Compact Flash) card using the PIC18F67J50. The actual firmware written is for reading a 2GB CF card. My boss ask me to try whether it can read a 8GB CF card or not. The result is it can't read.
May I ask is there any difference on a 2GB CF card and a 8GB CF card? Where can I find more info regarding reading files on CF using PIC?

 

[Golden Electronics]

plz post code so that check it

 

[maniac84]

plz post code so that check it

Sorry sir. The code is not with me right now.
Just want to know is there any internal difference between 2GB cf and 8GB cf?
Is there any addressing of memory difference?
Is there any internal structural difference?
Can I use the way of reading 2GB cf to read the 8GB cf?

 

[keith1200rs]

I don't know about CF cards but SD cards had a 2GB limit so to go above that they developed SDHC. There is example code on Microchip's site which is compatible with SD and SDHC. I assume the same limitation existed with CF cards.

Keith

 

[maniac84]

I don't know about CF cards but SD cards had a 2GB limit so to go above that they developed SDHC. There is example code on Microchip's site which is compatible with SD and SDHC. I assume the same limitation existed with CF cards.

Keith

Do you know what is the difference/limitation?

 

[keith1200rs]

Actually, now I am back at my computer and able to check, I think your problem is actually FAT16. To access more than 2GB (or possibly 4GB at a pinch) you need to use FAT32. So, your software needs to be able to read FAT32 formatted cards. https://en.wikipedia.org/wiki/CompactFlash#File_systems

Keith

 

[maniac84]

Actually, now I am back at my computer and able to check, I think your problem is actually FAT16. To access more than 2GB (or possibly 4GB at a pinch) you need to use FAT32. So, your software needs to be able to read FAT32 formatted cards. https://en.wikipedia.org/wiki/CompactFlash#File_systems

Keith

Is there any sample code or instruction on coding of how to read from FAT16 or FAT32 formatted cards?