void setup() {
  if (!Serial) Serial.println("serial is not ok");
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  // put your setup code here, to run once:

}
void loop() {
digitalWrite(3, HIGH);
delay(100
);
digitalWrite(3, LOW);

delay(100);

digitalWrite(5, HIGH);
delay(100);
digitalWrite(5, LOW);
;

  // put your main code here, to run repeatedly:

}