I did a GPS data logger application with PIC 16F819, my sd card format type fat32. i run my application and sent gps record to sd card.then, i couldnt see any text file or file. it saved it probably native raw type. I used a hex editor but this is not showed me relevant characters. My used project http://www.gedanken.demon.co.uk/gps-sd-logger/ How i can see the datas!!..
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From the linked page (emphasis mine),
The data is written to the SD card in blocks of 512 bytes (the native SD card block size). One block is written each second and padded to 512 bytes with zero bytes. Starting and stopping is recorded by a blank block in the SD card. There is no file system on the SD card so it needs to be read byte by byte (easy in Linux using a USB adapter and reading the raw device). To read the card I have a simple C program that extracts the NMEA data and writes one file for each time that the box was awake.
You need to read the card directly, which is easy on Linux or OS X but will differ between platforms. Feed the binary data to the C program he should have also posted on the site. (I didn't look.)
This assumes the hardware and everything is working correctly, which is not a safe assumption for a project simply built from online instructions. Probably you should contact the author of that page, he likely won't mind giving a little help.
Potatoswatter
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How i can use this command in linux fprintf(stderr,"Usage: gps-extract
[-skip nn]\n"); – UsTa May 18 '12 at 12:08 -
@UsTa that's a line of C code which prints an error message back to the console. To use it, compile it along with the rest of the C program. To use the *program*, pass it the path to the SD card, which should begin with `/dev/`. – Potatoswatter May 18 '12 at 12:10
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1@UsTa I have no idea, you're the one with the instructions. My guess would be that it allows you to skip a given number of records at the beginning of the log. – Potatoswatter May 18 '12 at 12:12