Are there any handheld gps units that you can add your own customized application software to? I am a firmware engineer, and I want to write code to add to the functionality of the GPS. Specifically, I want to allow my software to communicate with the GPS, and send data points that the GPS will display. Once displayed, I want my software to have the ability to change the color of the displayed points. I've tried Garmin and spoke with their representatives but Garmin does not allow any sort of dynamic update. Does anyone know of any GPSs that do? Thanks!
