void setup() {
  Serial.begin(9600);
  pinMode(12, OUTPUT);
  pinMode(2, INPUT);

}
int mim = 00;
int sec = 5;
int mus = 0;
int val;

void loop() {
if(digitalRead(2)==LOW){
  mus++;
val=analogRead(A2);
sec = map(val,0,1023,30,260);
}


while(sec > 60){
  sec=sec-60;
  mim++;
}






if(mus==1){
  delay(100);
  sec--;
if(sec == -1)
{
  mim--;
  sec = 59;
}


if (mim < 10)
{
  Serial.print("0");
}
Serial.print(mim);
Serial.print(":");


if (sec < 10)
{
  Serial.print("0");
}
Serial.println(sec);

}


if ((sec == 0 && mim == 0)&&(mus == 1))
{
  Serial.println("Der Timer ist Abgelaufen!");
  mus++;
}

else if(mus == 2){
  tone(10,260,50);
  digitalWrite(12, HIGH);
  delay(200);
  digitalWrite(12, LOW);
  delay(200);
}

else if(mus == 3){
  while(1);
}


}