Back to my newly discovered passion, Arduino.
I see that there is a lot of interest in these sensors and there isn’t much info about the protocol used by them. I have realised that is not really worth making your own sensors if your really want to make quality sensors, you can’t beat the price of mass produced ones no matter what. It is only interesting to build your own when they are find to find or they are not produced any more. I have stumbled across more information related to the protocol so I want it to share it here Oregon Scientific RF Protocols
I believe they can be replicated and they can be used easily, just try and have plenty of free time, there are many ways to read the data, my favourite remains Arduino.
I have found a Dutch project called Nodo Due which is based on Arduino and allows you used it for home automation and to receive raw information from some 433.92 Mhz sources. A very good project but is all in Dutch 
Available http://members.chello.nl/p.tonkes8/index.html quite an active forum and for me it seems like a good idea. I have offered to help but I don’t speak Dutch.
Here is the schematic:
A very good project based on Arduino and with a very few extra components, all of them easy to find. Tested by me and running fine on Arduino Uno, it does not compile in Arduino Mega 2560 and I haven’t much time trying to find out why.
Enjoy and play ..