I've got a Delorme Earthmate USB, and purchased the separate serial cable. I bought it with the intention of using roadmapgpsapp, with the option of connecting via USB with laptop in cases that called for a more total solution.

I guess I didn't research enough before delving into this project. Although the unit I bought outputs NMEA, I found this post that indicates that DeLorme may not be the way to go for my purposes. I believe the USB earthmate that I have still requires the DTR line to be high, and I really would rather not deal with a 12v -> 6v adaptor if another option is available.

So, what commercially available GPS unit is most easily interfaced with the empeg? Ideally, it would run off 12 volts and could be connected to the docking unit with just a male-male serial gender changer. I realize some wire hacking would be required to pull power, but the less the better. Oh, and I'd really like WAAS for better accuracy.

Suggestions?