void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
if(!Serial)Serial.println("serial is not ok");
pinMode(7, OUTPUT);
pinMode(6, OUTPUT);
pinMode(5, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(7, HIGH);
Serial.println("blue is on");
delay(500);
digitalWrite(7, LOW);
Serial.println("blue is off");
delay(1000);
digitalWrite(6, HIGH);
Serial.println("red is on");
delay(1500);
digitalWrite(6, LOW);
Serial.println("red is off");
delay(2000);
digitalWrite(5, HIGH);
Serial.println("yellow is on");
delay(2500);
digitalWrite(5, LOW);
Serial.println("yellow is off");
delay(3000);
}