Lpc2000

seangra wrote:

>Call me crazy, but how is $150 for something that you can get for 
>free a good value?  There must be dozens of open source FAT drivers 
>that could easily be ported, no?  Or am I missing something?
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You are, there really isn't any "good" FAT layers that are BSD 
licensed.  Most of what the stuff is very simplistic, only read a file, 
and write to a new file.  You don't have functions like: overwrite an 
existing file, etc.

Take a look at a recent Circuit Cellar, issue 176(?), for the article 
"Portable FAT Library for MCU Applications 
<http://www.dtweed.com/circuitcellar/caj00176.htm>".  That has the 
limitation that it will only create a new file, it will not overwrite an 
existing file (delete existing and create again).  Also, program does 
not implement fseek(), although you can make it seek if you alter the code.

IMO, there are two errors in that code as well, one deals with reading 
fragmented files, the other is reading from the MMC itself.  The example 
they give for reading from MMC is flawed.  The example works if you read 
the WHOLE file at once, subsequent calls to readPartialSector() will 
cause the MMC to return garbage data on occasion.

Seems that everyone has $$$ in their eyes when it comes to this stuff: 
write-once, charge-many.

I'm in the process of writing my own FAT layer that is integrated into 
NewLib (fopen, fclose, fputc, fseek, etc.).  The plan is to release the 
source under a BSD license.  While writing a FAT file driver is not that 
hard, it takes time.  I was disappointed to find that no one had written 
one and released the source!

Regards,

TomW




>--- In lpc2000@yahoogroups.com, "Joel Winarske" <joelw@i...> wrote:
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>>For anyone interested in implementing SD card with FAT12/FAT16 
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>support this
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>>is worth a look:
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>>http://tinyurl.com/3ozdl
>>-or-
>>http://www.prllc.com/productcart/pc/viewPrd.asp?
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>idcategory=10&idproduct=29
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>>It's a great value.
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>>I ported it to IAR, and have it running on an IAR LPC2148 KS board.
>>
>>Joel
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>Yahoo! Groups Links
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-- 
Tom Walsh - WN3L - Embedded Systems Consultant
http://openhardware.net, http://cyberiansoftware.com
"Windows? No thanks, I have work to do..."
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