const int ledPin = 13; // the pin that the LED is attached to
int incomingByte; 
String povel;
int i, x, y;

void setup() {
  Serial.begin(9600);
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  //if (Serial.available() > 0) {
    Serial.println("AHOJ!");
  //}
}

void loop() {
  if (Serial.available() > 0) {
    // read the oldest byte in the serial buffer:
    povel = Serial.readString();
    //Serial.print("Dosly prikaz: ");
    //Serial.println(povel);
    // if it's a capital H (ASCII 72), turn on the LED:
    if (povel.equals("PD\n")) {
      penDown();
    } else if (povel.equals("PU\n")) {
      penUp();
    } else if (povel.indexOf("BL")>=0) {
      zablikej(povel);
    } else{
      Serial.println("Prikaz nerozpoznan!");  
    }
  povel="";
  }  
}

void zablikej(String poveltext){
  String data;
  data = poveltext.substring(2);
  x = data.toInt();
  Serial.print("Zablikat ");
  Serial.print(x);
  Serial.println(" krat!");
  digitalWrite(ledPin, LOW);
  delay(1000);
  for (i=0;i<x;i++){
    digitalWrite(ledPin, HIGH);
    delay(100);
    digitalWrite(ledPin, LOW);
    delay(1000);
  }
}

void penUp(){
    digitalWrite(ledPin, LOW);
    Serial.println("Zhasnout!");
}

void penDown() {
    digitalWrite(ledPin, HIGH);
    Serial.println("Rozsvitit!");
}

void mr(String poveltext){
  String data1, data2;
  
}