Etrex Legend

[bigjim]

I was going to tag onto the other post on GPS but that might confuse the OP. I myself are confused enough. I have the Legend C which I have only realy used to tell me where I am and in what direction I am facing. This week I intend to improve my scant knowledge but the instruction book is either blinding me with science or I'm nodding off. I thought I was average intelligence. Jeez!. Anyway does anybody know, simply, how I just set the damn thing to navigate a track after I have downloaded a track from mapsource into the unit. The instructions don't seem to tell one how to do this. It does tell you how to navigate a route but evidently I can't download a route to the unit as I seem to have to purchase some mapping from garmin in order to create a route. Is this correct? Also as I am touring in France soon, is there a way I can download a French map into the unit that I can use to navigate?
Be very, very grateful for any simple directions on getting the most from this unit.

Jim.

[MockCyclist]

I'm not totally familiar with this model, but I think you can navigate a track as "trackback", ie, in reverse.

If you're transferring a track from MapSource, try reversing it first. You can do this in MapSource, double-click the track name, then "invert" and save. Transfer to GPS and try a "trackback".

Regarding routes, MapSource can open any .gpx file created from, say, bikehike, then you can transfer to GPS. So no, it's not essential to have Garmin mapping.

Here's somewhere you may be able to get French maps:
http://garmin.openstreetmap.nl/

[stewartpratt]

It's important to understand the difference between tracks and routes.

Tracks are simply a chain of simple points. Important things to note about tracks:
- every single point has a fixed position
- there is a limit of 500 points per stored track on most eTrex models (check the Garmin site for yours), although more for the 'active' track
- tracks can be displayed on the map
- tracks carry no navigational information

Routes are essentially a series of waypoints. Important things to note about routes:
- routes can be used to give turn-by-turn directions and bearings ets
- routes can be navigated "as the crow flies" (useful for orienteering with a map, no use for road cycling)
- IF your model supports autorouting AND you have road mapping in Mapsource (eg Metroguide Europe) AND Mapsource gives you the option to export autorouting data with the maps (checkbox at bottom of maps tab on left hand panel) then routes can be navigated along roads, with the map data being used to autoroute between waypoints in much the same way as Google Maps or Bikeroutetoaster (now it becomes useful for road cycling)
- if you find only the last part of the above point gets in your way then look up Metrogold
- (this is the really important one) the algorithm used by Mapsource to do autorouting is NOT THE SAME as the one used by the eTrex unit itself (or if it is then it's impossible to apply the same parameters); the result being that the route you see in Mapsource WILL NOT be the route you get on the unit. Well, probably. You need to be careful when plotting your route that you include enough waypoints in the right places in Mapsource that it doesn't go too far wrong (though it still can - I've had the unit try to send me round in circles)

The last bit makes everything a bit disappointing. What I do is make sure for each route I also have a matching track, so that if the two diverge I know to follow the latter. The routes are rendered in magenta on the map; I set my saved track to cyan and my active track to green, this seems to be about the clearest set of colours for seeing when the magenta and cyan diverge.

Now, to get that track, Garmin don't make life easy. I save the Mapsource file with the maps and routes, and export each route from Mapsource to Google Earth, which gives a KML file. From there I use GPSBabel to convert the KML to GPX, load that into Mapsource, copy it, reopen my original GDB file with the routes in, and paste the track in. (Phew! All for want of a "create track from route" button in Mapsource.)

As above, tracks can be converted to routes using the "trackback" feature on the eTrex. I've not used it but I rather assume it will give trun directions at every single point (ie every little bend in the road) rather than at the useful junctions (since it has no means of deriving this information), which would make it a dog to use. And would still require you to undergo all the above faff anyway.

Beats me that Garmin still haven't ever covered the extroardinarily obvious and simple use case of "create a route in Mapsource and then navigate along that exact same route". Effing mental if you ask me.

HTH.

[bigjim]

Thanks for all the help. I,ve done a 20mile circular run this morning. First I reversed the track and then told it to trackback. It then asked me to specify, shortest or fastest. Would not do anything until I made a choice. I just wanted it to follow the track, then it asked me to specify where to trackback to, which I did. Then off it went calculating its own route and did not follow the original track at all. Doohh. I originally thought I could design a route on Mapsource, transfer to garmin and then tell it to take me there. This does not seem to be the case. Is it me?

Thanks again. Jim

[patricktaylor]

... Anyway does anybody know, simply, how I just set the damn thing to navigate a track after I have downloaded a track from mapsource into the unit ...

First, make sure it is a track, not a route (I never use routes). Once you've transferred the track to the unit you have a wiggly line to follow on the map (assuming you are in the location of the track). It doesn't 'navigate' a track as such - just shows you a line to follow. It's easy.

[freezing77]

Thanks for all the help. I,ve done a 20mile circular run this morning. First I reversed the track and then told it to trackback. It then asked me to specify, shortest or fastest. Would not do anything until I made a choice. I just wanted it to follow the track, then it asked me to specify where to trackback to, which I did. Then off it went calculating its own route and did not follow the original track at all. Doohh. I originally thought I could design a route on Mapsource, transfer to garmin and then tell it to take me there. This does not seem to be the case. Is it me?

Thanks again. Jim

When it gives you the option of follow road or track you need to choose follow track.

That way it does exactly that rather than recalculating.

Some good info here
http://www.aukadia.net/gps/lwg_4.htm

and here
http://cycleseven.org/garmin-etrex-hcx-cycle-touring-setup

[stewartpratt]

Some good info here
http://www.aukadia.net/gps/lwg_4.htm

Indeed. The most pertinent page for this thread is this one: http://www.aukadia.net/gps/lwg_5.htm

(It says "I can think of 6 methods of navigating with a GPS, and some of these can be combined, for example I know someone who swears by methods 2 and 5 below, used together"... that combination of 2 and 5 is what I use, as above.)

[Astronomeradam]

I was going to tag onto the other post on GPS but that might confuse the OP. I myself are confused enough. I have the Legend C which I have only realy used to tell me where I am and in what direction I am facing. This week I intend to improve my scant knowledge but the instruction book is either blinding me with science or I'm nodding off. I thought I was average intelligence. Jeez!. Anyway does anybody know, simply, how I just set the damn thing to navigate a track after I have downloaded a track from mapsource into the unit. The instructions don't seem to tell one how to do this. It does tell you how to navigate a route but evidently I can't download a route to the unit as I seem to have to purchase some mapping from garmin in order to create a route. Is this correct? Also as I am touring in France soon, is there a way I can download a French map into the unit that I can use to navigate?
Be very, very grateful for any simple directions on getting the most from this unit.

Jim.

You can now plot routes using Google Maps and send it to your Garmin. Video from Garmin here: http://www.youtube.com/watch?v=N_p1x-fL2zc.

Assuming you are staying on the road then this will work perfectly.

[bigjim]

Thanks for the replies. I've sorted out how to create install and follow a track thenks to the clear instructions from Patrick of Cycleseven. Why a company like Garmin cannot produce a clear simple guide to it's product is beyond me.

Cheers. Jim.