Petr Tkac - jednoduchy odpocet casu

unsigned long prevMillis = 0;
int cas=10;  // 100 sekund

void setup() {
  Serial.begin(9600);
  pinMode(13, OUTPUT);  // Ledka
  pinMode(12, OUTPUT);  // Buzzer
  pinMode(11, INPUT_PULLUP);  // Tlacitko
  digitalWrite(13, LOW);
  Serial.print("Odpocet casu: ");
  Serial.println(cas);
  prevMillis=millis();
}

void loop() {
  if (prevMillis+1000 <= millis() && cas > 0)
  {
    prevMillis = millis();
    if (cas > 0)
    {
      cas--;
      Serial.print("Cas :");
      Serial.println(cas);
      if (cas < 6) digitalWrite(12, HIGH);  // Buzzer on
    }

    if (cas==0)
    {
      digitalWrite(13, HIGH); // LED on
      Serial.println("Stiskni reset pro novy odpocet:");
    }
  }
  if (!digitalRead(11) && cas==0)
  {
    Serial.println("Novy ddpocet casu:");
    cas=100;
    digitalWrite(12, LOW);  // Buzzer off
    digitalWrite(13, LOW);  // Ledka off
  }
}