How to read GPS coordinates from device via USB port

Question

I need to read GPS coordinates using a VB.NET program directly from a GPS device connected to the computer via USB (bluetooth also OK but prefer USB). My constraints are:

1. The computer running the software is NOT connected to the internet. It is a stand-alone machine in a moving vehicle.
2. I need to be able to read GPS coordinates from the device while the vehicle moves and use the device to perform location-aware queries on a local database
3. The GPS device can be anything (e.g. Garmin GPS or GPS card without display), as long at it can be purchased off the shelf or over the internet.
4. The user group for this solution is quite small (about 40 users).

I have already checked out GPSGate (http://gpsgate.com/) and emailed my requirements to them. They replied, and I quote: "I am sorry but we have no product for you." (end of reply).

I also checked out Eye4Software) and tried using their demo product but it does not pick up my Garmin Nuvi via USB. They responded to my questions but unfortunately their OEM product is an ActiveX dll and I am looking for a .NET based solution.

So if anyone has a "home-grown" solution based on the .NET framework, that can be easily duplicated, I would really appreciate it. Many thanks!

Answer 1

Most of the USB GPS pucks will speak a standardized protocol called NMEA 0183. There are several .net protocols out there that decode this protocol, see here for some pointers to get started.

So, if when shopping around you just check that the device is able to generate NMEA you should be up and running in a minimum of time, and at a reasonable cost.

EDIT: a "gps puck" is a GPS receiver shaped more or less like a hockey puck, like this one

For in-car use there are specific versions that can be fixed onto the vehicle's roof

They are pretty common (many online shops carry them) but select them based on the chip that's inside, the popular Sirf Star 3 is still a solid performer, stable and accurate. I haven't had the chance to play with its successor, the Sirf Star 4 yet, and I'm not implying these are the only good chips around, only that I got most experience with this chip.