Simple photoresistor example

Simple Arduino example to print out ambient light values using a photoresistor.

Components

• • 1 x photoresistor

  • 1 x 10k ohm resistor

  • 1 x Arduino Uno

  • 1 x breadboard

  • jumper wires

Setup

Arduino sketch

Inspect Serial monitor (9600) for light values.

/* 

Adapted from

http://playground.arduino.cc/Learning/PhotoResistor

Simple test of the functionality of the photo resistor

Connect the photoresistor one leg to pin 0, and pin to +5V

Connect a resistor (around 10k is a good value, higher

values gives higher readings) from pin 0 to GND. 

----------------------------------------------------

           PhotoR     10K

 +5     o---/\/\/--.--/\/\/---o GND

                   |

 Pin A0 o-----------

----------------------------------------------------

*/

int lightPin = A0;  //define a pin for Photo resistor

void setup()

{

    Serial.begin(9600);  //Begin serial communcation

    pinMode( lightPin, INPUT );

}

void loop()

{

    Serial.println(analogRead(lightPin)); //Write the value of the photoresistor to the serial monitor.

    delay(10); //short delay for faster response to light.

}