#define sensorpin 2

int SPstatus = HIGH;
void setup() {
  // put your setup code here, to run once:
pinMode(sensorpin, INPUT_PULLUP);
pinMode(12, HIGH);
digitalWrite(sensorpin, HIGH);
}

void loop() {
  // put your main code here, to run repeatedly:
  SPstatus = digitalRead(sensorpin);
  if (SPstatus==LOW){
    digitalWrite(LED_BUILTIN, HIGH);
    delay(300);
    digitalWrite(LED_BUILTIN, LOW);
    delay(300);
  }
  
}