Playing with a SkyTraq Venus GPS logger under Linux
I got a new toy today - a GPS logger. Got it as part of a magazine subscription deal - two issues + GPS logger for about $12. That magazine was not my kind of magazine, but getting a GPS logger delivered home for $12 was worth having to throw away two magazine issues :-). For other people trying to get this to work under Linux, the magazine in question was Aktiv Träning.
After some fiddling, I came to the conclusion that the device is based on the SkyTraq Venus chipset:
skytraq: Venus device found: Kernel version = 1.3.3, ODM version = 1.4.5, revision (Y/M/D) = 07/12/11
After plugging the device into an USB port, it appears as a serial port, in my case /dev/ttyUSB0. The data can be retrieved using GPSBabel, but it has to be the development version - the stable version does not feature the skytraq driver required. The development version is available via CVS from sourceforge, see http://sourceforge.net/projects/gpsbabel/develop for details on how to access CVS.
Once you have the development version of gpsbabel, getting the data is as easy as:
./gpsbabel -D 9 -i skytraq,initbaud=38400,baud=38400,erase -f /dev/ttyUSB0 -o gpx -F out.gpx
This will write the GPS coordinate log to out.gpx in the GPS Exchange format - a lightweight XML format.
The above command will also erase the log from the device, so the next download contains just the latest log.
Since I like playing with Google Earth, I also learned that the GPX can be converted into KML - the format Google Earth can read, by running:
./gpsbabel -i gpx -f out.gpx -o kml -F out.kml
Just open out.kml with Google Earth, and you'll see where the GPS logger has been.
On popular request, here's a few images of the device.
The label inside the battery compartment has the following text:
GT-750F/L-Lite GPS Receiver(Data Logger) RoHS CE FCC ID:VHP-750F Made in Taiwan CANMORE