AVR-Chat

I have seen that document on avr freaks. I WILL have to do some more reading in the SanDisk Secure Digital Card Product Manual. I was under the impression I could communicate to the card just like the eeprom I am using by giving a command to write and the address to start at. I have much more to learn. Thanks for your help.

Brian

--- In AVR-Chat@yahoogroups.com, "Tim Mitchell" <tim@...> wrote:
>
> ----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
>