void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  pinMode (22,OUTPUT );
  pinMode (17,OUTPUT );
  pinMode(15, OUTPUT);
}

void loop(){
// put your main code here, to run repeatedly:
 // this speeds up the simulation
 digitalWrite(22, HIGH);
 delay(2000);
 digitalWrite(22, LOW);
 digitalWrite(17, HIGH);
 delay (2000);
 digitalWrite(17, LOW);
 digitalWrite(15, LOW);
 delay (2000);
 digitalWrite(15, LOW);
}