void setup() {
  Serial.begin(9600);
  pinMode(5, INPUT_PULLUP);
  Serial.println();
}
void loop() {
  int t = 0;
  bool sw5 = digitalRead(5);
  while (sw5 == 0) {
    delay(1);
    t++;
    sw5 = digitalRead(5);
  }
  delay(100);
  if (t != 0) {
    Serial.println(t);
  }
}