int sL1 = 3;
int sL2 = 4;
int sL3 = 5;
int sL4 = 6;
int compteur = 0;
const int pause = 1000;

void setup() {
  Serial.begin(9600);
  pinMode(sL1, OUTPUT);
  pinMode(sL2, OUTPUT);
  pinMode(sL3, OUTPUT);
  pinMode(sL4, OUTPUT);
  delay(1000);
}

void loop() {

  if ( compteur >= 24 )
  {
  digitalWrite( sL1, LOW );
  digitalWrite( sL2, LOW );
  digitalWrite( sL3, LOW );
  digitalWrite( sL4, LOW );
  }
  else
  {
  digitalWrite( sL1, HIGH );
  digitalWrite( sL2, LOW );
  digitalWrite( sL3, LOW );
  digitalWrite( sL4, LOW );
  delay(pause);

 

  digitalWrite( sL1, LOW );
  digitalWrite( sL2, LOW );
  digitalWrite( sL3, HIGH );
  digitalWrite( sL4, LOW );
  delay(pause);

   digitalWrite( sL1, LOW );
  digitalWrite( sL2, HIGH );
  digitalWrite( sL3, LOW );
  digitalWrite( sL4, LOW );
  delay(pause);

  digitalWrite( sL1, LOW );
  digitalWrite( sL2, LOW );
  digitalWrite( sL3, LOW );
  digitalWrite( sL4, HIGH );
  delay(pause);

  compteur = compteur +4;
  Serial.print("pas = ");
  Serial.println(compteur);
  }
}