For my home automation project I am designing some sensor arrays to collect various type of data. Examples of sensor types include temperature, humidity, light intensity, proximity, sound and possibly a RFID reader. Each sensor array will be connected to an XBee Series 2 transceiver in order to be linked to the wireless network. When possible, a sensor will be designed to use an energy harvester which will allow the sensor array to run for long periods of time between charges.
An example of a typical array will be one with a temperature and light intensity sensor included in the circuit. Placing temp/light sensor arrays throughout the house will allow me to track hot and cold spots and help determine the best way to keep the house cool while using the least amount of energy. Living in Florida, it is rare to be concerned about it being too cold in the house or how to keep the house warm enough to fight off frostbite.
Typically in my house the master bedroom stays about 3-5 degrees cooler than the rest of the house. This is perfect at night as my wife likes to sleep in a cooler room. However once we are up in the morning and either at work or working at home, very little time is spent in the master bedroom or bath. If the cold air being delivered to the bedroom could be channeled to the living room or the office, it would keep the part of the house being utilized cooler without lowering the thermostat.
Using the light intensity sensors will help map out the brightness of the rooms being used at particular times of the day and determine which areas need additional light as it gets later in the day. What I hope to accomplish is to inexpensively add light to the kitchen/dining room by building lights using 20 Watt LEDs that would dim/brighten based on the amount of light needed. A 20 Watt LED has approximately 1000 lumens, which in incandescent wattage amounts is approximately 100+ Watts. A couple of LEDs could keep a high ceiling, open area nice and bright throughout the day and night.