void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
  pinMode(3, INPUT_PULLUP);
  pinMode(2, OUTPUT);
}
unsigned long duration;
int tog = 0;

void loop() {
  // put your main code here, to run repeatedly:
  duration = pulseIn(3, LOW);
  if(duration > 50){
    delay(150);
    if(tog == 0){
    digitalWrite(2, HIGH);
    tog = 1;
  }else{
    digitalWrite(2,LOW);
    tog = 0;
  }
  }
  Serial.println(duration);
}