/* 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. (see appendix of arduino notebook page 37 for schematics). ---------------------------------------------------- PhotoR 10K +5 o---/\/\/--.--/\/\/---o GND | Pin 0 o----------- ---------------------------------------------------- */ int lightPin = 0; //define a pin for Photo resistor int ledPin=11; //define a pin for LED void setup() { Serial.begin(9600); //Begin serial communcation pinMode( ledPin, OUTPUT ); } void loop() { Serial.println(analogRead(lightPin)); //Write the value of the photoresistor to the serial monitor. analogWrite(ledPin, analogRead(lightPin)/4); //send the value to the ledPin. Depending on value of resistor //you have to divide the value. for example, //with a 10k resistor divide the value by 2, for 100k resistor divide by 4. delay(10); //short delay for faster response to light. }