I've been looking around on DigiKey and other sites to see how expensive adding GPS capabilities to a robot down the line would be. I found plenty of modules for ~$35USD, which is about what I expected since many devices ~$100 have them built in.
I want to know what else is required to get started with adding GPS to my projects. Do I need to buy some kind of service, or is that basically included with the purchase of the module? Any device I've bought with GPS does not require any type of monthly payment for the service or anything, so I'm curious about this.
Also, other than modules, kits are often sold for $100-$300 or so. Are these kits required, or just tools to simplify development? What protocols or other software-side concepts should I be familiar with before starting to experiment with GPS?
I am a seasoned amateur C/C++ and Java programmer, and I have built and experimented with a few of the robot tutorials on this site, all using AVR MCUs, building my own boards. I am not familiar with any communication protocols, and I have not experimented with UART or USB.
I'm planning to be able to invest the time and money for bigger projects like this about a year from now, and I would like to have the tools and experience to take advantage of that. Thank you for any help.