Arduino security alarm project

 

int speaker=8;

void setup()

{

  pinMode(13,OUTPUT);

pinMode(A3,OUTPUT);

pinMode(A4,INPUT);

pinMode(A5,OUTPUT);

digitalWrite(A3,HIGH);

digitalWrite(A5,LOW);

digitalWrite(8,LOW);

digitalWrite(A4,LOW);

delay(5000);

}

void loop()

 {

  digitalWrite(A4,LOW);

  if(digitalRead(A4)==HIGH)

  {

    digitalWrite(13,HIGH);

  

}

if(digitalRead(13)==HIGH)

{

  for(int sound = 440; sound < 1000; sound+=25)

  {

    tone(speaker, sound, 50);

    delay(5);

   }

  

  for(int sound = 1000; sound > 440; sound-=25)

  {

    tone(speaker, sound, 50);

    delay(5);

    

  }

delay(10);

}

else

{

  digitalWrite(8,LOW);

}

 }