After about 3 weeks the Raspberry Pi RFM22B has arrived. The boards have been soldered and tested. There is some setup needed to get the SPI interface working, this is all explained at the top of some example code I am attaching at the bottom of this post. I built a total of 3 of these boards, each with a differently tuned RFM22B board. These boards are being used on my Quad copter as a small lightweight spectrum analyzer. I have attached both the code that I am currently using to drive the modules as well as a .zip file which can be directly submitted to Oshpark for fabrication. If you manage to try it, let me know how it works for you. The code I have written at the moment only covers setting the frequency, IF filter and pre-amp and allows the programmer to request the current RSSI level. I have also attached a LED which is directly connected to the GPIO pins just to play with.