responsive light
by BARRAGAN <http://barraganstudio.com>

Reads values from a photoresistor connected to the analog input pin 0. The value read from the sensor is proportional to the amount of light that hits the sensor surface. The value read is used to dim a light connected to the PWM Outpin 0

Created 1 May 2007
 

    
// responsive light 
// by BARRAGAN <http://barraganstudio.com> 

 
int val; 
 
void setup() 
{ 
  // nothing for setup 
} 
 
void loop() 
{ 
  val = analogRead(0);    // read analog input pin 0 (value in the range 0-1023) 
 
  // The luminosity of the LED will be proportional to te amount of light in the environment. 
 
  analogWrite(0, val/4);  // write the value to PWM output pin 0 (value in the range 0-255) 
 
  // if you want the luminosity of the LED to be inversely proportional to the amount of 
  // of light in the environment comment the previous line and use the line below instead: 
 
  //analogWrite(0, 255-val/4); 
 
  delay(100);             // wait 100ms for next reading 
}