#define red 5

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(red,OUTPUT);
  digitalWrite(red,HIGH);
  delay(2000);
}

void loop() {
 pinMode(red,OUTPUT);
  digitalWrite(red , HIGH);
  delay(2000);
  digitalWrite(red, LOW);
  delay(2000);
}