AVR-Chat

From: AVR-Chat@yahoogroups.com
[mailto:AVR-Chat@yahoogroups.com] On Behalf Of blue_eagle74
Sent: 18 February 2010 02:14 To: AVR-Chat@yahoogroups.com
Subject: [AVR-Chat] Re: small sd card

> Well, I guess standard SD cards for cameras and such.
> Wanted to use the SPI fuction of the card instead of the
> 4 bit mode. I have one made by Panasonic, 256M, not sure
> if this has the spi option. There is a guy sending me one
> that is 128M. I initally wanted a small one like a 16M
> because the data I am saving is quite small, using 512K
> eeprom right now.      
> 
> I haven't looked into it yet (I know 'google'), but is
> there a specific way to save data to the card so when the
> card is put into the computer it will open in excell? Do
> I just add ascII charactures for comma between the data? 

Not so simple unfortunately.

To do this you have to create a FAT filesystem on the card (or format
the card in the PC and use the filesystem thus created).
Have a look at FatFS which is a neat library for doing this (if you're
working in C). You just need to add functions to read and write a sector
of data to/from the card. Then it gives you standard file
open/read/write commands.

http://elm-chan.org/fsw/ff/en/sfatfs.html

If you name your file "xxx.xls" and put commas between the data, then
when you put the card into the pc and open the file, it would open with
excel (assuming your windows file associations are set up right).

-- 
Tim Mitchell

>
> ----Original Message----
> From: AVR-Chat@yahoogroups.com
> [mailto:AVR-Chat@yahoogroups.com] On Behalf Of blue_eagle74
> Sent: 18 February 2010 02:14 To: AVR-Chat@yahoogroups.com
> Subject: [AVR-Chat] Re: small sd card
> 
> > Well, I guess standard SD cards for cameras and such.
> > Wanted to use the SPI fuction of the card instead of the
> > 4 bit mode. I have one made by Panasonic, 256M, not sure
> > if this has the spi option. There is a guy sending me one
> > that is 128M. I initally wanted a small one like a 16M
> > because the data I am saving is quite small, using 512K
> > eeprom right now.      
> > 
> > I haven't looked into it yet (I know 'google'), but is
> > there a specific way to save data to the card so when the
> > card is put into the computer it will open in excell? Do
> > I just add ascII charactures for comma between the data? 
> 
> Not so simple unfortunately.
> 
> To do this you have to create a FAT filesystem on the card (or format
> the card in the PC and use the filesystem thus created).
> Have a look at FatFS which is a neat library for doing this (if you're
> working in C). You just need to add functions to read and write a sector
> of data to/from the card. Then it gives you standard file
> open/read/write commands.
> 
> http://elm-chan.org/fsw/ff/en/sfatfs.html
> 
> If you name your file "xxx.xls" and put commas between the data, then
> when you put the card into the pc and open the file, it would open with
> excel (assuming your windows file associations are set up right).
> 
> -- 
> Tim Mitchell
>