RFM12B Simple RF Transmission Demo
We use the RFM12B wireless transceiver module as an integral part of our emonTx design. Here's a bit of general information about the module.
For a simple example of how to use transmit variables between a couple of RM12B modules see: https://github.com/openenergymonitor/RFM12B_Simple
http://www.hoperf.com/pro/rf/cob/RFM12B.htm