int Lpin = 12;
int Bpin = 5;

int currentState;
int lastState = LOW;
int ledState = HIGH;


void setup() {
  Serial.begin(9600);
  pinMode(Lpin, OUTPUT);
  pinMode(Bpin, INPUT);

}

void loop() {
  currentState = digitalRead(Bpin);
  if(lastState == LOW && currentState == HIGH) 
  {
    ledState = !ledState;
    digitalWrite(Lpin, ledState);
    Serial.println("stlacene");
  
  }
  else if(lastState == HIGH && currentState == LOW) 
  {
    Serial.println("uvolnene");
  }

  lastState = currentState;
  delay (50);
}