int32_t prevMillis = 0;
bool prevState = true;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Starting");

}

void loop() {
  bool currState = digitalRead(14);
  if(currState == false && currState != prevState){
    Serial.printf("T: %dms\n", millis()-prevMillis);
    prevMillis = millis();
  }
  prevState = currState;
  
  delay(10);
}