int led = 5;
int pir = 2;
int pirState = LOW;
int val = 0;
int summer = 7;
const int schalter = 8;

void setup() {
  pinMode(led, OUTPUT);
  pinMode(pir, INPUT);
  pinMode(summer, OUTPUT);
  Serial.begin(9600);
  }
void loop(){
  val = digitalRead(pir);
  if (val == HIGH) {
    digitalWrite(led, HIGH);
    playTone(300, 160);
    delay(150);


    if (pirState == LOW) {
      Serial.println("Bewegung erkannt!");
      pirState = HIGH;
  }
  } else {
      digitalWrite(led, LOW);
      playTone(0, 0);
      delay(300);
      if (pirState == HIGH){
      Serial.println("Bewegung Ende!");
      pirState = LOW;
  }
  }
  }
void playTone(long duration, int freq) {
    duration *= 1000;
    int period = (1.0 / freq) * 1000000;
    long elapsed_time = 0;
    while (elapsed_time < duration) {
        digitalWrite(summer,HIGH);
        delayMicroseconds(period / 2);
        digitalWrite(summer, LOW);
        delayMicroseconds(period / 2);
        elapsed_time += (period);
  }
  }