void setup() {
  // put your setup code here, to run once:
  pinMode(12, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int taster = digitalRead(21);

  if(taster == 1) {
    digitalWrite(12, HIGH);
  } else {
    digitalWrite(12, LOW);
  }
  delay(200);
}