void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  if(!Serial) Serial.println("serial isnt ok");
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  // green on
  digitalWrite(3, HIGH);
  Serial.println("green");
  delay(5000);
  // green off
  digitalWrite(3, LOW);
  digitalWrite(4, HIGH);
  // yellow on
  Serial.println("yellow");
  delay(2000);
  // yellow off
  digitalWrite(4, LOW);
  // red on
  digitalWrite(5, HIGH);
  Serial.println("red");
  delay(5000);
  // yellow on
  digitalWrite(4, HIGH);
  Serial.println("yellow");
  delay(2000);
  // red off
  digitalWrite(5, LOW);
  // yellow off
  digitalWrite(4, LOW);
}