To use AFSK simply select it as a connection method (instead of tcp, udp or http).
There is a quite long synchronization part at the beginning of the message (1s) , which can be used to trigger a VOX or something homebrewn as well as your brain to push the PTT in time.
No need for fast reflexes. 1s is quite enough I think (maybe changed to user adjustable later)
Please note, that the build.xml hat to be adapted (incl librarys in libs).
Bastian Müller