#include <Arduino.h>
#define RELAY 25


void setup() {
  Serial.begin(115200);
  pinMode(RELAY,OUTPUT); 
  Serial.println("*** Start Program ***");
  }

void loop() {
  digitalWrite(RELAY,1);
  delay(1000);

  digitalWrite(RELAY,0);
  delay(1000);
}
NOCOMNCVCCGNDINLED1PWRRelay Module