Interruptor - Arduino

const int switchPin = 2;
int valSwitch = 0;
void setup() {
  Serial.begin(9600);
  pinMode(switchPin, INPUT);
}
void loop() {
    valSwitch = digitalRead(switchPin);
    if(valSwitch == HIGH){
      Serial.println("0");
      delay(30);
    }
    if(valSwitch == LOW){
      Serial.println("1");
      delay(30);
    }
}