I'm trying to use my eTrex Venture HC as a GPS unit for my netbook program for marine charting. I downloaded the Garmin simulator (Spanner) that translates the USB connection to serial data so that NEMA data is recognized by the marine charting software. But, the Spanner program cannot "find" my eTrex when I plug it into the USB port.. Any hints as to the problem??
That is a bottom-of-the-line model and I don't think it supports what you need. Look at page 38 of the owners manual here:
http://static.garmincdn.com/pumac/eTrexLegendHCx_OwnersManual.pdf
Note that it says "The available interface format is Garmin". Now compare that to page 68 of the GPSMap 60csx manual here:
http://static.garmincdn.com/pumac/GPSMAP60CSx_OwnersManual.pdf
Note that you can choose Garmin, NMEA or Text as an interface format on the 60csx. These additional options aren't available on your unit.
What I'm not sure of, however, is whether you could use GPSGate for this. It is a program that runs on your PC and can translate between different data formats. For example, it can be used to receive position data from a Nuvi, which isn't supposed to be possible either.
You could try downloading the free trial and see if it works: http://gpsgate.com/products/gpsgate_client
The thing is, if it comes down to actually spending money then you might as well just buy a USB GPS receiver - they are pretty cheap, around $60 or less I believe.