21 – Light Activated LED

int lightPin = 0; //define pin for Photo resistor
int ledPin=13;//define a pin for LED
void setup()
{
Serial.begin(9600); //Begin serial communication
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
}