The first link you posted is the OSPi user manual. All OSPi hardware setup steps are in the OSPi user manual. The second one is for OpenSprinkler, but it also includes descriptions of firmware 2.1.7 (which is a unified firmware that runs on both OSPi and OpenSprinkler). So if you are looking for hardware setup, follow the OSPi user manual. If you are looking to check firmware features, use the second one.