New eTrex Software version

[Salvatore]

4.30 has been released:

http://www8.garmin.com/support/download_details.jsp?id=5553

Changes made from version 4.20 to 4.30:
Improved 'Save Portion' track feature. When saving a portion, the device now remembers that position in the track log so it can be used as a track segment for future portion saving.
Fixed possible erroneous track point on power on.
Fixed formatting issue with certain map names in the map information list.

I'm hoping that erroneous track point fix will finally sort the trip odometer out.

It (upgrading to 4.3) hasn't worked for me. Today I rode from A to B, turned the Etrex 20 off, did things, then when I turned it back on, it created a spurious trackpoint at A before realising I was at B, inserting a lightning-fast return trip to A and back again and adding a few km to the trip.

[Kim]

Bah!

[frankly frankie]

When an E20/30 is switched off, it (over)writes a single-point gpx file with the current location.  (The file is called   .Position.gpx   note the initial dot)
I've no idea what use this is supposed to be, since if it's hot-starting or warm-starting it certainly doesn't need this information, and if it's cold-starting the chances are it'll be somewhere else anyway.  But presumably it reads this file on startup and if it's been moved in the interim that may be why the effect John describes happens - though obviously it shouldn't, and it doesn't explain what ocurred in the exact case above where the GPS wasn't moved.

[Kim]

I've no idea what use this is supposed to be, since if it's hot-starting or warm-starting it certainly doesn't need this information, and if it's cold-starting the chances are it'll be somewhere else anyway.

Presumably not for GPS operation, as that should be internal to the chipset, anyway.

Maybe something sensible and UI-related, like the timezone to use and what order to sort the nearest waypoints list in, before it has a GPS fix.

[Ben T]

When an E20/30 is switched off, it (over)writes a single-point gpx file with the current location.  (The file is called   .Position.gpx   note the initial dot)
I've no idea what use this is supposed to be, since if it's hot-starting or warm-starting it certainly doesn't need this information, and if it's cold-starting the chances are it'll be somewhere else anyway.  But presumably it reads this file on startup and if it's been moved in the interim that may be why the effect John describes happens - though obviously it shouldn't, and it doesn't explain what ocurred in the exact case above where the GPS wasn't moved.

I've tried changing that to try to make it think it's in a different position, when it's in my house and has no signal, and it doesn't work, so it must remember its position some other way as well.

[frankly frankie]

Well yes a GPS when it switches on knows the time (almost exactly = hot start; approximately = warm start) and it knows which of the satellites are above the horizon** so doesn't have to hunt for them in the noise, and that is what facilitates the rapid fix.

** of course if you've just taken it on a long-haul flight that might confuse it a bit when you first switch it on - even so it only takes about 2 minutes (Manchester to S.India) - much faster than a cold start (when it has been unused for months).