int opoz = 1;

int IN1 = 2;
int IN2 = 3;
int IN3 = 4;
int IN4 = 5;
int led = 13;

void turn(int krok){
switch(krok){
   case 0:
     digitalWrite(IN1, LOW); 
     digitalWrite(IN2, LOW);
     digitalWrite(IN3, LOW);
     digitalWrite(IN4, HIGH);
   break; 
   case 1:
     digitalWrite(IN1, LOW); 
     digitalWrite(IN2, LOW);
     digitalWrite(IN3, HIGH);
     digitalWrite(IN4, HIGH);
   break; 
   case 2:
     digitalWrite(IN1, LOW); 
     digitalWrite(IN2, LOW);
     digitalWrite(IN3, HIGH);
     digitalWrite(IN4, LOW);
   break; 
   case 3:
     digitalWrite(IN1, LOW); 
     digitalWrite(IN2, HIGH);
     digitalWrite(IN3, HIGH);
     digitalWrite(IN4, LOW);
   break; 
   case 4:
     digitalWrite(IN1, LOW); 
     digitalWrite(IN2, HIGH);
     digitalWrite(IN3, LOW);
     digitalWrite(IN4, LOW);
   break; 
   case 5:
     digitalWrite(IN1, HIGH); 
     digitalWrite(IN2, HIGH);
     digitalWrite(IN3, LOW);
     digitalWrite(IN4, LOW);
   break; 
     case 6:
     digitalWrite(IN1, HIGH); 
     digitalWrite(IN2, LOW);
     digitalWrite(IN3, LOW);
     digitalWrite(IN4, LOW);
   break; 
   case 7:
     digitalWrite(IN1, HIGH); 
     digitalWrite(IN2, LOW);
     digitalWrite(IN3, LOW);
     digitalWrite(IN4, HIGH);
   break; 
   default:
     digitalWrite(IN1, LOW); 
     digitalWrite(IN2, LOW);
     digitalWrite(IN3, LOW);
     digitalWrite(IN4, LOW);
   break; 
}
}

void setup() {
pinMode(IN1, OUTPUT);
pinMode(IN2, OUTPUT);
pinMode(IN3, OUTPUT);
pinMode(IN4, OUTPUT);
pinMode(led, OUTPUT);

}

void loop() {
//for(int b = 1; b < 17; b++){ //pełen obrót wału silnika
	for(int a = 0; a < 8; a++){ //pełna sekwencja, 4 kroki
  	turn(a);
  	delay(opoz);
	}
//}


}