How long until someone's running TCP over this? It's just a matter of time until we can use this with a cantenna to control very-long range drones. Combine this with one of the winners of the Groupon DroneGames[1] and you could control a fleet of cheaply-made drones across a wide range. Is anyone interested in creating an autonomous fleet to patrol their property and airspace?

[1]http://techcrunch.com/2012/12/02/dronegames-in-san-francisco...

It would have been nice to show the FM modulation equation in use along with the code. I say this because most people underestimate the complexity of FM modulation and instead write an approximation that doesn't create the hoped-for result.

Here's a reference for the actual math:

http://arachnoid.com/phase_locked_loop/index.html#Detailed_D...

(search below the provided bookmark for "Frequency-modulated reference oscillator")