Ardunio: PIR Sensor + LED Setup

gistfile1.txt

boolean alreadyLow = true;
int pirPin = 3;
int ledPin = 2;

void setup(){
  Serial.begin(9600);
  pinMode(pirPin, INPUT);
  digitalWrite(pirPin, LOW);
  pinMode(ledPin, OUTPUT);
}

void loop(){
  if(HIGH == digitalRead(pirPin) && alreadyLow){
    alreadyLow = false;            
    digitalWrite(ledPin, HIGH);
    Serial.print("motion detected - ");
    Serial.println(millis());
  } else if( LOW == digitalRead(pirPin) && !alreadyLow){
    alreadyLow = true;            
    digitalWrite(ledPin, LOW);
    Serial.print("motion no longer detected - ");
    Serial.println(millis());
  }
  delay(100);
}