In my ongoing compulsion to connect things to other things, I did not want to be locked in with a design to one RF solution.
There are a few minimalist options available now. The Hope-RF RFM12 is a favorite, the newer Hope-RF RFM70 or 73 and not forgetting Sparkfun with the Nordic nRF24L01 solutions
I wanted to use the sparkfun SIL footprint as my 'fit-all' footprint. and make small breakout boards so that I could use any of the 3 options as a plug-in.
The breakouts need space for an on-board regulator to enable use with 3.3V or 5V. Dont fit the reg for 3,3V, cut a track and fit the reg for 5V. The RFM12 also needs spaces for some resistors if used with 5V. Its inputs are not 5V tolerant.
This is the first version I came up with. Its before I decided to use the Sparkfun footprint as the model.
New version will use the Sparkfun footprint.
I dont need to solder the RF board on to the 'main' board, its just a plug-in, fit if required. One footprint does all.
The Sparkfun versions are available pretty much everywhere and now I have options to use RFM12's in the same socket or the RFM70.
The Sparkfun version.
This is what the new versions will adhere to.