Upload Garmin map (gmapsupp.img) to Garmin eTrex Legend via serial connection.
The motivation was when QLandkarteGT development stopped and its successor (Qmapshack) removed map upload feature.
Note that eTrex Legend has only 8 MB available memory for custom maps. Throw aways details that you don't need. Also note that average upload speed is 8.7 kB/s hence it can take more than 15 minutes to finish the upload.
By interacting with eTrex Legend (and maybe other Garmin devices too) via serial connection in an unexpected way it is possible to brick your device. This is based on a personal experience. Although I did manage to unbrick it you may not be that lucky hence:
- use at your own risk and do not complain if your Garmin can no longer boot
- backup your data first
- be prepared for a hw upgrade
Heavily based on code from:
- qlandkartegt/garmindev (https://sourceforge.net/projects/qlandkartegt/)
- pygarmin (https://github.com/quentinsf/pygarmin)
Big thanks to authors of both (and related) projects.
Run etrex_upload.py -h to get available command-line options.
For a more complete session see example.sh. Please note that the script
requires prior installation of osmconvert, mkgmap and splitter.
You can watch a recorded session at https://asciinema.org/a/YsXvwqaeRfgLFkcHZAQYusbYW.
# transfer waypoints from device to PC
gpsbabel -w -i garmin -f /dev/ttyUSB0 -o gpx -F /tmp/waypoints.gpx
# transfer tracks from device to PC
gpsbabel -t -i garmin -f /dev/ttyUSB0 -o gpx -F /tmp/tracks.gpx
# show current position (output to stdout)
gpsbabel -i garmin,get_posn -f /dev/ttyUSB0
# turn off
gpsbabel -i garmin,power_off -f /dev/ttyUSB0
Further documentation at https://www.gpsbabel.org/htmldoc-development/fmt_garmin.html.