int bit1=13;
int bit2=12;
int bit3=11;
int bit4=10;
int i;


void setup() {
  // put your setup code here, to run once:
 pinMode(bit1, OUTPUT);
 pinMode(bit2, OUTPUT);
 pinMode(bit3, OUTPUT);
 pinMode(bit4, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  for(i=0;i<16;i++){
    switch(i){
    case 0: digitalWrite(bit1, LOW);
            digitalWrite(bit2, LOW);
            digitalWrite(bit3, LOW);
            digitalWrite(bit4, LOW); 
            delay(1000);}{
    case 1: digitalWrite(bit1, HIGH);
            delay(500);
            digitalWrite(bit2, LOW);
            digitalWrite(bit3, LOW);
            digitalWrite(bit4, LOW); 
            delay(1000);   }   
    case 2: digitalWrite(bit1, LOW);
            digitalWrite(bit2, HIGH);
            delay(500);
            digitalWrite(bit3, LOW);
            digitalWrite(bit4, LOW); 
            delay(1000); 
    case 3: digitalWrite(bit1, HIGH);delay(500);
            digitalWrite(bit2, HIGH);delay(500);
            digitalWrite(bit3, LOW);
            digitalWrite(bit4, LOW); 
            delay(1000);   
    case 4: digitalWrite(bit1, LOW);
            digitalWrite(bit2, LOW);
            digitalWrite(bit3, HIGH);delay(500);
            digitalWrite(bit4, LOW); 
            delay(1000); 
    case 5: digitalWrite(bit1, HIGH);delay(500);
            digitalWrite(bit2, LOW);
            digitalWrite(bit3, HIGH);delay(500);
            digitalWrite(bit4, LOW); 
            delay(1000);  
    case 6: digitalWrite(bit1, LOW);
            digitalWrite(bit2, HIGH);delay(500);
            digitalWrite(bit3, HIGH);delay(500);
            digitalWrite(bit4, LOW); 
            delay(1000);      
    case 7: digitalWrite(bit1, HIGH);delay(500);
            digitalWrite(bit2, HIGH);delay(500);
            digitalWrite(bit3, HIGH);delay(500);
            digitalWrite(bit4, LOW); 
            delay(1000);             
    case 8: digitalWrite(bit1, LOW);
            digitalWrite(bit2, LOW);
            digitalWrite(bit3, LOW);
            digitalWrite(bit4, HIGH);delay(500);
            delay(1000);   
    case 9: digitalWrite(bit1, HIGH);delay(500);
            digitalWrite(bit2, LOW);
            digitalWrite(bit3, LOW);
            digitalWrite(bit4, HIGH);delay(500);
            delay(1000);         
    case 10: digitalWrite(bit1, LOW);
            digitalWrite(bit2, HIGH);delay(500);
            digitalWrite(bit3, LOW);
            digitalWrite(bit4, HIGH);delay(500);
            delay(1000);                           
    case 11: digitalWrite(bit1, HIGH);delay(500);
             digitalWrite(bit2, HIGH);delay(500);
             digitalWrite(bit3, LOW);
             digitalWrite(bit4, HIGH);delay(500);
             delay(1000);      
    case 12: digitalWrite(bit1, LOW);
             digitalWrite(bit2, LOW);
             digitalWrite(bit3, HIGH);delay(500);
             digitalWrite(bit4, HIGH);delay(500);
             delay(1000); 
    case 13: digitalWrite(bit1, HIGH);delay(500);
             digitalWrite(bit2, LOW);
             digitalWrite(bit3, HIGH);delay(500);
             digitalWrite(bit4, HIGH);delay(500);
             delay(1000); 
    case 14: digitalWrite(bit1,LOW);
             digitalWrite(bit2,  HIGH);delay(500);
             digitalWrite(bit3, HIGH);delay(500);
             digitalWrite(bit4, HIGH);delay(500);
             delay(1000);     
    case 15: digitalWrite(bit1,HIGH);delay(500);
             digitalWrite(bit2,  HIGH);delay(500);
             digitalWrite(bit3, HIGH);delay(500);
             digitalWrite(bit4, HIGH);delay(500);
             delay(1000);                          
                                       }
                                       /*
                                       
  if(i==0){
  digitalWrite(bit1,HIGH);
  delay(500);
  digitalWrite(bit1, LOW);
  delay(500);
  }
  digitalWrite(bit1,HIGH);
  delay(500);
  digitalWrite(bit1, LOW);
  delay(500);
  digitalWrite(bit2, HIGH);
  delay(500);
  digitalWrite(bit2, LOW);
  delay(500);
  digitalWrite(bit3, HIGH);
  delay(500);
  digitalWrite(bit3, LOW);
  delay(500);
  digitalWrite(bit4, HIGH);
  delay(500);
  digitalWrite(bit4, LOW);
  delay(500);


}
*/