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Terribly sorry for asking this very basic question but I'm at the pulling out hair stage. I bought the Garmin eTrex Legend HCx to use when cycling the North Sea Cycle Route. I have never used OSM nor a Garmin GPS so a large portion of the technical jargon used on these pages are very confusing.

Firstly the micro-SD card is in the Garmin and it has full battery life. My time so far has been spent trying to export a part of the UK map using all of the options (XML/osmrender etc....) and nothing shows up on my GPS. Mapsource is open but nothing shows up through that - i can't locate any files on my computer that i have tried to download and have definitely had no success at downloading these files that you then unzip. I have been searching for days endlessly through web forums hoping to get a beginners basic guide about getting an OSM map onto the GPS but nothing.

I understand this is a very time consuming question to have answered so I do really really appreciate in advance any basic steps taken to get a map onto GPS. Thankyou very much

asked 18 Apr '11, 14:41

aliNSCR's gravatar image

accept rate: 0%

edited 18 Apr '11, 16:31

SomeoneElse's gravatar image

SomeoneElse ♦

When it comes to obtaining the map, you've got two basic options:

1) Download a map from somewhere (easier, but less customisable)

2) Create your own.

If you want to download a map, there's a list of providers here. There are lots of options - some routeable and some not, customised for different uses, etc. I've heard people recommend the ones here.

If you want to create your own, have a read of this answer which is intended to be a quick "how to" for using mkgmap to create your own map. You don't export the map from the OSM web site; typically you'd use an extract of e.g. the UK data.

Edit: People are linking to this question, so it also makes sense to link to these step-by-step instructions too.

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answered 18 Apr '11, 15:54

SomeoneElse's gravatar image

SomeoneElse ♦
accept rate: 16%

edited 19 Apr '15, 21:34

The easiest way: get hands on a precompiled (=ready to use map), e.g. by following a link in the wiki. This map will be called GMAPSUPP.IMG

  1. Set your unit into mass storage mode (connect it with a computer via USB), or take out the card and copy the file with a cardreader onto it (see 2).
  2. copy the GMAPSUPP.IMG file to the folder GARMIN (or create this folder if not available) with your operating system (you do not need Mapsource or any other dedicated software for this step).
  3. unmount the USB-Device from your computer (eject in the filemanager)

You should be done. Take care that the map is not bigger then 2 GB (and 2025 map tiles) for individual maps, because the file system and firmware Garmin uses cannot deal with them.

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answered 18 Apr '11, 15:39

dieterdreist's gravatar image

accept rate: 3%

edited 18 Apr '11, 22:11

thankyou you so much for your help - im just tyring to download now and fingers crossed it works. Can i ask something...if you choose to add another map to your device after downloading GB map - say i want to add Norway - will that one then over ride and delete the previous one? thankyou again im dead pleased that you people take the time to help. have a lovely day, ali

(18 Apr '11, 16:27) aliNSCR

If you're downloading a gmapsupp.img to manually copy to a microSD card then yes, I believe that you can only have one of those on an eTrex at once. However, if you're creating the gmapsupp.img yourself you can combine maps of various parts of the world into one gmapsupp.img without problems. I'm not sure what options you've got within Mapsource; personally I don't use it to transfer maps.

(18 Apr '11, 16:38) SomeoneElse ♦

Managing downloads of several different maps is probably easier if you use MapSource. Some of the OSM on Garmin providers have versions which will install directly in MapSource using a fairly typical Windows installation process. I think the MapSource documentation covers how to use multiple maps.

Merging multiple maps for direct card installation requires using the mkgmap program. It's probably best to proceed in easy steps: nothing is really complicated, but there are quite a few things to get used to.

(18 Apr '11, 17:18) SK53 ♦

If you want to select different maps on your Garmin, you'll probably need something more like a Colorado or Oregon or similar high-end model that allows multiple .img files instead of the eTrex. Or use to select multiple areas to be merged into a single map for your garmin. Your call.

(18 Apr '11, 21:16) Baloo Uriza

Your comments seem to indicate a high degree of confusion. If the available advice and information on the wiki, the sites of providers of OSM maps for Garmin etc. are not adequate, then I would really suggest considering buying a pre-loaded card with an OSM-derived map for cyclists.

These are sold by Andy Allan, the creator of OpenCycleMap on his website shop. This only covers Britain & Ireland, but saves the hassle and you get an extra sim card for your Garmin.

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answered 18 Apr '11, 21:23

SK53's gravatar image

SK53 ♦
accept rate: 22%

I connected my new Garmin etrex 30 to my computer via the usb and tried several times (taking ~30mins a time!) to copy GMAPSUPP onto the sd card in the Garmin but it wouldn't appear in the folder named GARMIN that I'd created on the sd card. However putting the CARD IN THE ADAPTER AND DIRECTLY INTO THE COMPUTER not only copied GMAPSUPP quicker but worked when the sd card was reinserted into the etrex.

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answered 28 Sep '13, 13:51

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Mini Schnauzer
accept rate: 0%

I use the files compiled by "talky toaster" google talky toaster finds it, i down load the file contours-routable-GMAPSUPP (could take 30 mis on Broad Band ) create a folder on your PC called "garmin" decompress or unzip the download into this folder( again may take a few minutes) now shorten the name to GMAPSUPP. connect your garmin GPS with the micro SD installed to your PC with the USB lead, on the garmin go to main menu select "set up" then select "interface" then you should see on the garmin screen "USB Mass Storage" high lighted in yellow press the joy stick button, (your garmin will appear as an external drive to your PC ). Now just copy the garmin folder and contents (it should hold the unzipped GMAPSUPP that you created earlier) onto the GPS/memory card, again this will take a few minutes when finished you should have OSM on your garmin. Best that you print these instruction off as each stage must be done correctly for it to work. good luck it took me a few attempts to get it to work the first time.let us know how it goes

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answered 19 Apr '11, 00:27

andy%20mackey's gravatar image

andy mackey
accept rate: 4%

edited 11 May '13, 23:38

Ho! glad to see you've solved the problem while I was composing my answer, hopefully the instructions will be of use to another user

(19 Apr '11, 00:34) andy mackey

I dont know what im doing wrong i can't even get the computer to recognise the device. Does this mean there is some sort of compatablility issues with the device? I just want to get a map onto the device to see how effective the overlays are. I just tried the GPs in another computer and nothing it could not detect it lost on this. I did manage to download the files but could not unzip them and then not even find the device, like i mentioned. sooo frustrating - im really not normally this confused when it comes to computers.

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answered 18 Apr '11, 18:14

aliNSCR's gravatar image

accept rate: 0%


Did you switch the device to mass storage mode? You have to do this. This should go like this: Main Menu > Setup > Interface > USB Mass Storage Now it should pop up in the file manager.

(18 Apr '11, 18:33) dieterdreist

this is i did manage to open USB mass storage - all fine and i can see the unzipped folder in there BUT it wont let me unzip it. on our hard standing computer there is no option to select 'unzip' just keeps bringing up about burning to a disc(?) So i plugged in device to my laptop (of which i know can unzip files) and again nothing is available to allow me to unzip - only talking about extracting files which i have selected but this is to take 40mins?? is this right - am im totally loosing the plot here? thankyou - from a slighty insane and going googely eyed alison

(18 Apr '11, 19:57) aliNSCR

It's all sorted now. Managed to get hold of a friend who talked me through everything on the phone. Thankyou for your time and effort to help me in previous notes. Ali

(18 Apr '11, 21:18) aliNSCR

Well perhaps your frien can phone me now as all I have is the base map on the Garmin I got I seem to be able to upload routes on the the Garmin etrex Vista But of course not having a decent map on here (the Garmin ive got just has base map) when I put my route on it it just shows a track over a yellow background as the roads are too minior to show on the base map, As I don't have a big micro SD card in it yet (one in the post) I though I could just down load some of teh local tile segentments near me which are not very big , about 365kb's and that would go on to the micro SD I have at present just so I can get used to the procdure? like the way of doing it. but wor is me It seems not Iv'e gone though all the above re the usb setup/ interface/ mass storage thing and its painfully blatant that I'm missing something Anybody any ideas Perhaps a Dummies guide lol regards Antnee

(20 Mar '13, 09:52) Antnee

Antnee My current talky toaster full GB map is only 500mb his instructions and maps ARE good. see my answer above and this one

(20 Mar '13, 11:46) andy mackey

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question asked: 18 Apr '11, 14:41

question was seen: 95,024 times

last updated: 19 Apr '15, 21:34

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum