Arduino Sketches

motion_buzzer.c

int pirPin = 2;
int piezoPin = 12;
int pirState = LOW;
int pirInputValue = 0;

void setup() {
  pinMode(piezoPin, OUTPUT);
  pinMode(pirPin, INPUT);

  Serial.begin(9600);
}

void loop() {
  pirInputValue = digitalRead(pirPin);

  if (pirInputValue == HIGH) {
    tone(piezoPin, 1000);

    if (pirState == LOW) {
      Serial.println("Motion detected!");

      pirState = HIGH;
    }
  } else {
    noTone(piezoPin);

    if (pirState == HIGH) {
      Serial.println("Motion ended!");

      pirState = LOW;
    }
  }
}