#define sw 2
#define led LED_BUILTIN //13
#define grd 4
void setup() {
 Serial.begin(9600);
 pinMode(sw,INPUT);
 pinMode(led, OUTPUT);
 pinMode(grd, OUTPUT);
 digitalWrite(grd,LOW);



}

void loop() {
 
  if(digitalRead(sw) == LOW)
     {
       delay(20);
       digitalWrite(led, HIGH);
      Serial.println(digitalRead(sw));
     }else 

         digitalWrite(led, LOW);
         Serial.println(digitalRead(sw));
           
           }