void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  if(!Serial) Serial.println("Ошибка, стоп машина!");
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(2, HIGH);
  Serial.println("Red ON");
  delay(5000);
  digitalWrite(3, HIGH);
  Serial.println("Yellow ON");
  delay(2000);
  digitalWrite(2, LOW);
  Serial.println("Red OFF");
  digitalWrite(3, LOW);
  Serial.println("Yellow OFF");
  digitalWrite(4, HIGH);
  Serial.println("Green ON");
  delay(5000);
  digitalWrite(4, LOW);
  Serial.println("Green OFF");
  digitalWrite(3, HIGH);
  Serial.println("Yellow ON");
  delay(2000);
  digitalWrite(3, LOW);
  Serial.println("Yellow OFF");
}