// parametry definovane uzivatelem
byte RELE = 2;
int SONDA = A4;
byte MAX = 5;

// systemove promenne
int HLADINA = 0;
byte REG = 0;

void setup() {
  pinMode (RELE, OUTPUT);
  digitalWrite (RELE, LOW);
  Serial.begin (9600);
}

void loop() {
  HLADINA = analogRead(SONDA);

  // citac testu maximalni hladiny
  if (HLADINA <= 500) if (REG < MAX) REG++;

  Serial.print (HLADINA);
  Serial.print ("(");
  Serial.print (REG);
  Serial.print (")");

  // minimalni hladina, vypnout cerpadlo
  if (HLADINA > 500) {
      if (digitalRead (RELE) != LOW) {
        Serial.print (" - minimalni hladina, cerpadlo ");
        delay (6000);
        digitalWrite (RELE, LOW);
        Serial.print ("VYPNUTO");
      }
    REG = 0;
  }

  // maximalni hladina, zapnout cerpadlo
  if (REG >= MAX) {
    if (digitalRead (RELE) != HIGH) {
      Serial.print (" - maximalni hladina, cerpadlo ");
      delay (2500);
      digitalWrite (RELE, HIGH);
      Serial.print ("ZAPNUTO");
    }
  }

  Serial.println ();
  delay (1000);
}