int ledPin = 8;
int btnPin = 12;
int btnRead;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);
  pinMode(btnPin, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  btnRead = digitalRead(btnPin);
  Serial.println(btnRead);
  delay(50);
  if (btnRead == 0) {
    digitalWrite(ledPin, HIGH);
  }
  else {
    digitalWrite(ledPin, LOW);
  }
}