int boton=9;
int led=4;
void setup() {
 Serial.begin(9600);
 pinMode(boton, INPUT);
 pinMode(led, OUTPUT);

}

void loop() {
if(digitalRead(boton)==HIGH)
{
 Serial.println("apagado");
 digitalWrite(led, LOW);

}
else 
{
  Serial.println("encendido");
   digitalWrite(led, HIGH);
}
}