Nice write up on using Micro:Bit with Radio

The Micro:bit is a nice cheap dev platform for learning on.  Its not arduino, but it has alot of build int functions (bluetooth, lots of LEDs, buttons, giro, etc etc) for a cheap price (found some for $15).  This write up goes over the radio part of the system and how to use it.

http://www.instructables.com/id/Radio-Signals-on-Microbit/