The problem: I have an Etrex30x ver3.0. Up now I have always downloaded map tiles from garmin.openstreetmap.nl, installed them in Mapsource and used Mapsource to send the map to the Etrex. No problem. Recently I tried to get a current map from download.bbbike.org but the site provides only pre-compiled gmapsupp files that the etrex rejects with the message ‘can’t authenticate maps. contact . . .’
My solution: a) split the gmapsupp with the ‘Split’ option in Gmaptool (*see link below for instructions) and b) install the resulting *.img files using MapsetToolKit. At this point I can open Mapsource and carry on as usual. Problem solved.
Software needed:
- Gmaptool.exe http://www.gmaptool.eu/en
- cgpsmapper.exe https://www.gpsfiledepot.com/tools/cgpsmapper.php (used with Gmaptool)
- MapsetToolKit.exe https://sites.google.com/site/cypherman1
– with linux it works perfectly using wine
*Link: https://www.garminworldmaps.com/how-to-install/convert-gmapsupp-img-mapsource/
This process probably works with other devices that use similar firmware:
Oregon 700/750, Edge 520/820/1000, Etrex 20x, Etrex Touch 25/35, GPS Map 64, Montana 610, 680 . . .
Hope this helps