const int operationPin = 2;
bool operationCompleted = false;

void setup() {
  pinMode(operationPin, INPUT_PULLUP);
  Serial.begin(9600);
}

void loop() {
  if (digitalRead(operationPin) == LOW) {
    operationCompleted = true;
  }

  if (operationCompleted) {
    Serial.write(1);
    operationCompleted = false;
  }
  
  delay(50);
}