The whole project consists of four hardware/software parts:

1. Outdoor components:

Sesnsors that collect outdoor weather reading.
Further description: http://kcotar.org/arduino-weather-station-1/

2. Data receiver:

A piece of hardware that is connected to the PC over RS232 interface and collects data that were gathered and sent by an outdoor componeents.

3. Weather station:

Used to download weather data saved by receiver and show them on the LCD screen. It also have some capability of storing extreme values of reading.
Further description: http://kcotar.org/arduino-weather-station-2/

4. Home automation

A system that shares some of the components (power source, display etc.) with the weather station and is used to control some hardware parts (lights, sensors) of the room. Components are driven by a simple IR remote. Capability of alarm clock that automaticaly turns on ligths in the room and piezo buzzer and uses them as a way to wake up the person sleeping in the room.
Further description: http://kcotar.org/simple-home-automation-using-arduino/