View difference between Paste ID: 3Mt6buhn and k50uLsZX

 // Laser Security Alarm
 // BY Stigern, www.stigern.net
 
 int ldr_readings = 0;
 int AlarmPin = 10;
 
 void setup()
 {
  // Setting up Serial communication!
  // I use this for calibration first, to read what values I
  // get when it got the laser in center, and what value I
  // get when it's not in the center. So that I know what
  // to put in the if statements.
   Serial.begin(9600);
 }
 
 void loop()
 {
   // Read from the analog 0 and put it into the integer.
   // So that we can use the if statement to ask if it's
   // something blocking the light or now.
   ldr_readings = analogRead(0);
 
   // Just so we can see the values from the LDR
   // Prints the integer to us via serial. Used
   // for calibration when adjusting 100 and 50.
   Serial.println(ldr_readings);
 
   // Should we activate the alarm?
   // Yepp, if we get a value higher than 100.
   if (ldr_readings > 100)
   {
      digitalWrite(AlarmPin, HIGH);
   }
 
   // Or should we deactivate it?
   // Yes if we get a value lower than 50.
   if (ldr_readings < 50)
   {
      digitalWrite(AlarmPin, LOW);
   }
 }