void setup() {
Serial.begin(115200);
pinMode(25, OUTPUT);
pinMode(26, OUTPUT);
pinMode(27, OUTPUT);
pinMode(21, OUTPUT);
pinMode(22, OUTPUT);
pinMode(23, OUTPUT);
pinMode(17, INPUT);
}

void loop() {
  int a=digitalRead(17);

  if (a==1)
  {

  Serial.println("signal1 stop");
  digitalWrite(25, HIGH);
  digitalWrite(26, LOW);
  digitalWrite(27,LOW);

  Serial.println("signal2 go");
  digitalWrite(21, HIGH);
  digitalWrite(22, LOW);
  digitalWrite(23,LOW);
  delay(3000);

  Serial.println("signal1 ready");
  digitalWrite(25, LOW);
  digitalWrite(26,HIGH);
  digitalWrite(27, LOW);

  Serial.println("signal2 slow");
  digitalWrite(21, LOW);
  digitalWrite(22, HIGH);
  digitalWrite(23,LOW);
  delay(3000);

  Serial.println("signal1 go");
  digitalWrite(25, LOW);
  digitalWrite(26, LOW);
  digitalWrite(27, HIGH);

  Serial.println("signal2 stop");
  digitalWrite(21, LOW);
  digitalWrite(22, LOW);
  digitalWrite(23,HIGH);
  delay(3000);

  Serial.println("signal1 slow");
  digitalWrite(25, LOW);
  digitalWrite(26,HIGH);
  digitalWrite(27, LOW);

  Serial.println("signal2 ready");
  digitalWrite(21, LOW);
  digitalWrite(22, HIGH);
  digitalWrite(23,LOW);
  delay(3000);
}
else
{
  digitalWrite(25, LOW);
  digitalWrite(26, LOW);
  digitalWrite(27, LOW);
  digitalWrite(21, LOW);
  digitalWrite(22, LOW);
  digitalWrite(23, LOW);
  delay(0);
}
}