int vitesse = 3000;
int pin1 = 9;
int pin2 = 10;


void setup() {
  // put your setup code here, to run once:
pinMode(pin1, OUTPUT);
pinMode(pin2, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:

digitalWrite (pin1, HIGH);
digitalWrite (pin2, LOW);
delay (vitesse);
digitalWrite (pin1, LOW);
digitalWrite (pin2, HIGH);
delay (vitesse);

}