long timePress=0;
int btnBefore=0;
int buzzerStatus=0;
#define buzzer 26
void setup() {
  Serial.begin(115200);
  pinMode(13, INPUT);
  pinMode(buzzer,OUTPUT);
  
}

void loop() {
  int reading=digitalRead(13);
  if(reading&&btnBefore!=reading){
    timePress=millis();
  }
  if(reading&&millis()-timePress>30&&timePress>0){
    timePress=-1;
    buzzerStatus=!buzzerStatus;
    if(buzzerStatus){
      tone(buzzer, 261);
    }
    else noTone(buzzer);
  }
  
  btnBefore=digitalRead(13);
}