hello all,

after some (late nite) investigations on the internet, I ended up here. I was researching for a cheap GPS logger .. and found many of them, but they were not affordable.

what I am looking for is a little device that would take some NMEA data from a GPS receiver mouse (5V, RS-232), eventually filter out some unneeded data (STX, ETX, etc) and save it into a file (or files) on an SD or MMX card. after some days of travel, I would get the SD-card from this device and transfer the data to my PC for postprocessing.

NMEA data looks basically like this (and that's what I would like to see in the files):

$GPRMC,131700.074,A,4628.8544,N,00716.8242,E,22.13 0221,132.60,260705,,*3E
$GPGGA,131701.074,4628.8504,N,00716.8306,E,1,05,1. 7,1080.8,M,48.1,M,9.7,0000*49
$GPGSA,A,3,08,10,29,28,26,,,,,,,,7.9,1.7,7.7*36
$GPRMC,131701.074,A,4628.8504,N,00716.8306,E,21.89 6268,133.45,260705,,*37
$GPGGA,131702.074,4628.8463,N,00716.8367,E,1,05,1. 7,1081.5,M,48.1,M,10.7,0000*79
$GPGSA,A,3,08,10,29,28,26,,,,,,,,7.9,1.7,7.7*36

(the GPS mouse can be programmed to limit the data to the GPGCA or GPRMC strings. optional postprocessing of the strings might turn each line into something like "time, latitude, longitude, altitude", but this is only needed with smaller SD-cards and very long logging. the strings come in every second. with ca. 80bytes per second, this makes about 48MB for a full week of 24h logging.)

I believe that the following HW thingy would be fullfilling my needs: http://www.compsys1.com/workbench/On...c_project.html

is this correct?

the next step is to have the right software to convert the RS-232 data stream into file(s) on the SD-card (from what I read here on the board, the filesystem on the SD/MMC card is the main challenge). then somehow this code needs to be compiled and transferred into the HW thingy.

frankly, I do not have a clou what to do next. I used to program 6809 and 8051, but that is centuries ago. and I had access to dev-environments at the company I was working for. today, I only have a pc at home...

the greatest thing that could happen is when someone of you has already done something like I want, and would share it with me.

thanks

dan