The Adafruit Analog Light Sensor comes pre-assembled and fully tested on a handy breakout board. We have included a small header strip in case you want to use it on a breadboard. This can be installed in a few simple steps:
Wiring for Arduino
Wiring this sensor is very simple. It can be powered by 2.3-6V, and has an analog output of up to 3v max. To use with an Arduino, wire it as follows:
VCC -> 5v
OUT -> A0
GND -> GND
SInce the output range of the sensor is 0-3v, for maximum resolution, it is best to use the 3.3v pin for your voltage reference. To do this, run a jumper from 3.3v
on your Arduino. In your code, be sure to specify "analogReference(EXTERNAL);"
When using an external analog reference, it is important to specify analogReference(EXTERNAL) in your code before performing any analogRead() operations. Otherwise, your external reference will be shorted to the default internal 5v reference. This can damage your Arduino.
One nice thing about this little sensor is that it doesn't require a microprocessor for interfacing. You can use this sensor to make simple light-activated circuits or even an analog light meter. The sensor output varies from about 5-50uA. With the on-board 68K resistor, this translates to a range of about 0.3v to 3v.