LDR

gistfile1.txt

/*
** Nightlight LDR test program
** Created 06 Feb 2010
**
** This example code is in the public domain.
** www.hobbytronics.co.uk
*/

int sensorPin = A0;            // select the input pin for the ldr
unsigned int sensorValue = 0;  // variable to store the value coming from the ldr

void setup()
{
  pinMode(13, OUTPUT);
  //Start Serial port
  Serial.begin(9600);        // start serial for output - for testing
}

void loop()
{
  // read the value from the ldr:
  sensorValue = analogRead(sensorPin);     
  if(sensorValue<400) digitalWrite(13, HIGH);   // set the LED on
  else digitalWrite(13, LOW);   // set the LED on
  
  // For DEBUGGING - Print out our data, uncomment the lines below
  //Serial.print(sensorValue, DEC);     // print the value (0 to 1024)
  //Serial.println("");                   // print carriage return  
  //delay(500);  
}