- GPS-Logger: Royaltek RGM-3800
This user uses or has experience with a Royaltek RGM-3800 and is willing to answer questions on it from OSM users.
- Tracker: Garmin Vista HCx
This user uses or has experience with a Garmin Vista HCx and is willing to answer questions on it from OSM users.
- Desktop: Ubuntu (Hardy Heron)
- Notebook: Ubuntu (Lucid Lynx)
- with built-in "Ericsson F3507g Mobile Broadband Minicard Composite Device"
- mini-PCI UMTS card with GPS funtionality
Some RGM-3800 Hints
Speaking from experience: The first parts of recorded tracks tend to be inaccurate if the RGM-3800 is switched on the first time a day (cold start).
- the firmwareupdate (RoyalTek Ver 220.127.116.11) is applied and
- enable logging of statistic information (satellite count, satellite fix and Horizontal Dilution Of Precision (HDOP)) with the following command:
rgm3800.py --device=/dev/ttyUSB0 format 4
I get the best tracks with an interval of two seconds between points:
rgm3800.py --device=/dev/ttyUSB0 interval 2
Get track number 42 from the device:
rgm3800.py --device=/dev/ttyUSB0 track 42 >track.nmea
Convert from NMEA to GPX format:
gpsbabel -i nmea -f track.nmea -o gpx -F track.gpx
Discard all trackpoints with a HDOP above 4 (1 to 4 very good, 4 to 8 medium and greater 8 bad). Information on HDOP (german)
gpsbabel -i gpx -f track.gpx -x discard,hdop=4,hdop -o gpx -F track-clean.gpx
The resulting file is now minus the imprecise trackpoints.
If further editing is necessary I use the graphical java program Prune.
java -jar prune_05.jar
Sometimes it is useful to retrieve not just one track from the device. Small Bash-Script which does download from device and conversion to gpx and kml with gpsbabel:
#!/bin/bash # Script takes two numbers (from-track / to-track) as parameters for i in `seq $1 $2`; do echo -e "Retrieving track number $i ...\n"; rgm3800.py --device=/dev/ttyUSB0 track $i >track$i.nmea; echo "NMEA to KML..."; gpsbabel -i nmea -f track$i.nmea -o kml -F track$i.kml; echo "NMEA to GPX..."; gpsbabel -i nmea -f track$i.nmea -o gpx -F track$i.gpx; echo "Filtering GPX - only HDOP over 4..."; gpsbabel -i gpx -f track$i.gpx -x discard,hdop=4,hdop -o gpx -F track$i-clean.gpx; echo "$i End!"; done;
The last track
The last track on the RGM-3800 is sometimes incompletely retrieved. This error happens with the commandline python-tool and with the official windows application. Remedial action: Record another few points as a new track and the now second last track can be retrieved correctly.
Ericsson F3507g Links
- Commandline GPLv3 python linux/mac tool for RGM-3800
- Detailed (german) review of the RGM-3800
- Detailed (german) step-by-step-information for the firmwareupdate of a RGM-3800
- C-sourcecode of a alpha-state GPLv3 program to operate the RGM-3800
- rgm3800-client.c was announced on this comment page