Maps for UK & France on Garmin Legend Cx

Friday 21 December 2007 15:27 | General

A while back, I put a picture of my newly acquired toy. I since used it for various things, including records of cycle rides (eg. London-Cambridge in 2006.

I also use it to geotag most of my photos (although nothing has cropped up on the website yet).

The Garmin Legend Cx is great for this kind of tasks but (obviously) can't compete with "Sat Navs". The basic embedded map is quite primitive and doesn't provide much more than an overviews of Motorways & major roads. It is possible to buy better maps either as CDs or micro-SD cards but it's not cheap and since it had a very limited interest for me I never bothered.

But, thanks to the nice folks of OpenStreetMap, it is possible to upload better maps to GPS... including the Garmin ones.

Here is the page of pre-compiled maps for some European countries:

Instructions are not terribly clear and using Sendmap didn't work for me.

So, here is how I do it (instruction under Linux but it's roughly the same for other OS):

  • 1 - Download of a map in garmin format from (wiki page above)
  • 2 - Rename it as gmapsupp.img
  • 3 - Put the GPS in "USB Mass Storage" mode (Setup / Interface / USB Mass Storage)
  • 4 - Mount the GPS as an external disk (like you would with a usb key or external hard drive) (eg something like mount /dev/garmin /media/garmin)
  • 5 - create a Garmin directory if not already present (something like mkdir /media/garmin/Garmin)
  • 6 - cp the gmapsupp.img file created in 2 in this directory (eg: cp gmapsupp.img /media/garmin/Garmin/gmapsupp.img)
  • 7 - unmount the GPS (eg umount /media/garmin)... this actually synchronises the data and can take a while!
  • 8 - unplug the USB connection on GPS which should reboot
  • 9 - check the new card is loaded (it's on the "copyright/start up" page, "Find" page, "Setup / Map / Information" page)... have fun!