View Full Version : Weird Legend C

24th February 2006, 04:16 PM
Hello all

I put new lithium batteries in my Etrex Legend C today and when I turned it on I had the altimeter on it in the menu and altimeter stuff in the setup menu! I thought only the Vistas had the altimeter!
so I turned it off and back on again and it's gone!
does anyone know why it would have come up? or how I can get it back?


28th February 2006, 02:25 PM
Did the altimeter actually work? I'd say that the legend c and the vista are identical units, and the altimeter is disabled on the Legend C through the firmware.

Sounds like there may be a way to hack it ;)

1st March 2006, 07:36 PM
it didn't appear to be working but I didn't get long to play with it!
its really weird that it even came up!
and other than batteries I can't figure out what I did to make it come up.

7th March 2006, 06:21 AM
Some software glitch occured that caused code execution to jump to
the altimeter routines.
The software to display altimeter/compass readings exists in all Legends.
So does the software to callibrate the compass.
You can see text relating to this clearly if you open one of the firmware files
with a hex editor.
But the altimeter/compass hardware does not exist in the cheaper units, so they can never work.

Power fluctuation is a classic method used to deliberately cause this type of
behaviour in microcontroller circuits, but I wouldn't suggest trying it on purpose,
since the same method can corrupt memory contents.
If part of the firmware loader became corrupted the unit may actually lose it's
functionality completely, and become to stupid to even reload it's firmware from your PC (ie broken).