void setup() {
  pinMode(16, OUTPUT);
  pinMode(17, OUTPUT);   
  pinMode(18, OUTPUT);   
  pinMode(19, OUTPUT);   
  pinMode(21, OUTPUT);    
  Serial.begin(9600);
}

void turn(){
  digitalWrite(16, HIGH); 
  delay(100);            
  digitalWrite(16, LOW);
  delay(100);         
digitalWrite(17, HIGH); 
  delay(100);            
  digitalWrite(17, LOW);
  delay(100);
  digitalWrite(18, HIGH); 
  delay(100);            
  digitalWrite(18, LOW);
  delay(100);
  digitalWrite(19, HIGH); 
  delay(100);            
  digitalWrite(19, LOW);
  delay(100);
  digitalWrite(21, HIGH); 
  delay(100);            
  digitalWrite(21, LOW);
  delay(100);

  digitalWrite(19, HIGH); 
  delay(100);            
  digitalWrite(19, LOW);
  delay(100);
  digitalWrite(18, HIGH); 
  delay(100);            
  digitalWrite(18, LOW);
  delay(100);
  digitalWrite(17, HIGH); 
  delay(100);            
  digitalWrite(17, LOW);
  delay(100);
  digitalWrite(16, HIGH); 
  delay(100);            
  digitalWrite(16, LOW);
  delay(100);
}

void right(){
  digitalWrite(16, HIGH); delay(200);
  digitalWrite(17, HIGH); delay(200);
  digitalWrite(18, HIGH); delay(200);
  digitalWrite(19, HIGH); delay(200);
  digitalWrite(21, HIGH); delay(200);
  digitalWrite(16, LOW);
  digitalWrite(17, LOW);
  digitalWrite(18, LOW);
  digitalWrite(19, LOW);
  digitalWrite(21, LOW);
  delay(500);
}

void left(){
  digitalWrite(21, HIGH); delay(200);
  digitalWrite(19, HIGH); delay(200);
  digitalWrite(18, HIGH); delay(200);
  digitalWrite(17, HIGH); delay(200);
  digitalWrite(16, HIGH); delay(200);
  digitalWrite(16, LOW);
  digitalWrite(17, LOW);
  digitalWrite(18, LOW);
  digitalWrite(19, LOW);
  digitalWrite(21, LOW);
  delay(500);

}
void loop() {
  
turn();
erial.printlnS("<--------->");
  delay(1000);
right();
right();
  right();
  delay(1000);
  left();
left();
  left();
  
}