LED Lux Reactor
My project is a simple fading LED light that turns on when the light sensor is not exposed to light. When the sensor is covered up, the on-board LED on the Arduino UNO lights up.
I used the Arduino Starter kit in creating my project: http://store.arduino.cc/product/K000007
I also used the Lux sensor TSL 2561: http://www.adafruit.com/product/439
The tutorial I used was on Instructables.com. Here is the link: http://www.instructables.com/id/Arduino-Fading-Light
To put it together, I first sodered the Lux sensor to 7 pins. The Vin pin on the sensor connected to Ground on the Arduino. The Addr pin on the sensor connected to Analog 0 on the Arduino. Finally, the SCL pin on the sensor connected to the 5 volt pin on the Arduino.
In order to operate the LED, all you have to do is shield the Lux sensor from light. This causes the LED to turn on. The amount of light the sensor sees determines how low the light will be.