int ledPin = 14;                 // pin for LED
int pirPin = 12;                 // pin for PIR sensor
int pirState = LOW;              // we start, assuming no motion detected
int val = 0;                     // variable for reading the pin status

void setup() {
  pinMode(ledPin, OUTPUT);       // declare LED as output
  pinMode(pirPin, INPUT);        // declare PIR sensor as input

  Serial.begin(115200);
}

void loop() {
  val = digitalRead(pirPin);     // read input value
  if (val == HIGH) {             // check if the input is HIGH
    digitalWrite(ledPin, HIGH);  // turn on the LED 
    if (pirState == LOW) {
      Serial.println("Motion detected!");
      pirState = HIGH;
    }
  } else {
    digitalWrite(ledPin, LOW);   // turn off the LED
    if (pirState == HIGH) {
      Serial.println("Motion ended!");
      pirState = LOW;
    }
  }
}