Hi Matt, Do your sd_card and hd libs use the info in the fat32? There is no guarantee that files created are contiguous. Also how will you mark the actual end of the file/contents?
William On Jul 31, 11:05 am, mattschinkel <[email protected]> wrote: > Hey Sunish, > > It depends on your application. > > For low memory usage, you can do it right now. My lib does not yet > create file names. Creating file names would use lots of memory. So, > do this: > 1. put your data media into your PC and create 365 files (one for each > day of the year) or however many you need, and make them the size of > the max data. > 2. defragment your data media (fragmented files will also require more > memory, there is a constant in the lib) > 3. use the fat32 lib to go into the file > 4. use the sd_card lib or hd lib to write to the file. > > I also suggest you make one or two files for misc data, such as what > the last file is that you wrote to. After 1 year, you can go back and > write over the last years data. > > I can work on it so it can create files, but it will use much more > memory. starting with 512 bytes for a sector buffer. What PIC do you > plan to use? I soon plan to be able to record compressed sound, so > I'll be working on this soon. > > Matt. > > On Jul 31, 4:03 am, Sunish Issac <[email protected]> wrote: > > > > > Hello Matt, > > > I have not personally tested your libs yet. But looks like you've done a > > great job in accomplishing everything in jal. > > > As Vasi, I'm too looking for a data logging application. I might need to > > create one file each per day so, its not going to be more than 365 per year > > and I don't need long file names. > > The process would be to create a new text file daily, append data and then > > close the file say every hour. > > > Can this functionality be accomplished with your libs or do I have to do > > lots more additional work ? > > > Sunish > > > On Sat, Jul 31, 2010 at 9:49 AM, mattschinkel > > <[email protected]>wrote: > > > > I can put a constant in my lib for using long/short file names because > > > of the patent. I don't quite understand if reading long file names is > > > ok. I know writing them is not ok. > > > > The patent says "long AND short filenames", but the work around uses > > > "long OR short filenames" or something like that. I was planning to > > > read more about the technical stuff. Here is some detail on the work > > > aroundhttp://lwn.net/Articles/338981/ > > > > I heard that the royalty fee for FAT32 is $0.50 per product sold. > > > > Short file names is fine for logging data, but it is not so good for a > > > product user. 8 letters is not really enough to describe something. > > > > Matt. > > > > On Jul 30, 11:37 pm, William <[email protected]> wrote: > > > > Hi Matt, > > > > > OK, I read your link - indeed there is an issue with 'long file > > > > names'. However the elm-chan provides 'long file names' as a separate > > > > feature, so if you stay with short file names, you should be OK. > > > > Please read his statements about this here: > > > > >http://elm-chan.org/fsw/ff/en/appnote.html > > > > > Thank you, > > > > > William > > > > > On Jul 30, 6:40 pm, mattschinkel <[email protected]> wrote: > > > > > > William, Read this: > > >http://www.microsoft.com/whdc/system/platform/firmware/fatgendown.mspx > > > > > > You can read about MS vs TomTom > > > > > > This VFAT does some things to get around the patent. Here is a good > > > > > description.http://www.desktoplinux.com/news/NS4980952387.html > > > > > > Vasi, my lib is quite simple to use and user friendly :) By changing > > > > > the constants in my sample, I can get my fat32 to run at 6594 program > > > > > memory, and 399 ram. This is small enough for any 18F. > > > > > > Matt. > > > > > > On Jul 30, 3:17 pm, William <[email protected]> wrote: > > > > > > > I don't think there is any royalty issue with fat32? I can mount > > > such > > > > > > volumes in Ubunu/Linux without any royalty fees and create files and > > > > > > filenames. > > > > > > > Fat32 files are not necessarily contiguous. So be careful if you > > > want > > > > > > to try and write-over an existing fat32 file with a low-level > > > > > > library. Check out Elm-Chan's petite library -- he made a nice GPS > > > > > > data logger for Atmel/Arduino cpu. His full-featured library fits > > > > > > on my 18F parts (in C), so should be doable in JAL also. > > > > > > > William > > > > -- > > > You received this message because you are subscribed to the Google Groups > > > "jallib" group. > > > To post to this group, send email to [email protected]. > > > To unsubscribe from this group, send email to > > > [email protected]<jallib%[email protected]> > > > . > > > For more options, visit this group at > > >http://groups.google.com/group/jallib?hl=en. -- You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/jallib?hl=en.
