#include <Arduino.h>
#define BUTTON 16
#define  RELAY 26

void setup() {
 
  Serial.begin(9600);
  pinMode(BUTTON, INPUT_PULLUP);
  pinMode(RELAY, OUTPUT);
  digitalWrite(RELAY, LOW);
}

void loop() {
 if(digitalRead(BUTTON) == LOW){
  digitalWrite(RELAY,HIGH);
  Serial.println("LED ON");
  delay(500);
 }
 else{
  digitalWrite(RELAY, LOW);
  Serial.println("LED OFF");
  delay(500);
 }
}