int pinR = 13;
int pinY = 12;
int pinG = 11;

int pinB = 2;

int barva = 0;

int hodnota = HIGH;

int OFF = HIGH;
int ON = LOW;


void setup() {
 pinMode (pinG, OUTPUT);
 pinMode (pinY, OUTPUT);
 pinMode (pinR, OUTPUT);

 pinMode (pinB, INPUT);

 Serial.begin(9600);

 digitalWrite(pinR, OFF);
 digitalWrite(pinY, OFF);
 digitalWrite(pinG, OFF);

}

void loop(){
hodnota = digitalRead(pinB);

Serial.println(hodnota);

if (barva >= 4){
  barva = 0; 
}

if (hodnota == HIGH){
  switch(barva){
    case 0:
        digitalWrite(pinR, ON);
        digitalWrite(pinY, OFF);
        break;

    case 1:
        digitalWrite(pinY, ON);
        break;

    case 2:
        digitalWrite(pinR, OFF);
        digitalWrite(pinY, OFF);
        digitalWrite(pinG, ON);
        break;

    case 3:
        digitalWrite(pinG, OFF);
        digitalWrite(pinY, ON);
        break;

    case 4:
        digitalWrite(pinY, OFF);
        digitalWrite(pinR, ON);
        break;
  }
  
  barva ++;
 }


 

 
 
delay(200);
}