Run vs_community.exe to install Visual Studio Community 2013 and study source code examples.

ProtocolSandbox - should be used for new protocol development.
ProtocolSandbox ASCII Protocol Example - ASCII protocol example.
ProtocolSandbox HEX Protocol Example - HEX protocol example.

Develop protocol on your own, send source code and protocol documentation to info@gps-server.net, we will verify it and integrate into your server.