It is a refactored mix between :
- OneWire sensor reading on arduino site : http://playground.arduino.cc/Learning/OneWire
- Oregon Scientific protocol with arduino : http://connectingstuff.net/blog/encodage-protocoles-oregon-scientific-sur-arduino/ . Specification is here : http://wmrx00.sourceforge.net/Arduino/OregonScientific-RF-Protocols.pdf
It allows to simulate a THGN122/123 / THGN132 / THGR122/228/238/268 thermometer with an arduino and a one wire sensor (for example to send pool temperature to a RFXCOM receiver).