Arduino Code

const int buttonPin = 2; //the button is on port 2 int buttonState=0; //if pressed int ledInPin = 1; //the led is on 1

void setup() {

 //turn on internl led
 pinMode(17, OUTPUT);
 digitalWrite(17, HIGH);
 
  // initialize the button pin as a input:
  pinMode(buttonPin, INPUT);
  //initalize input monitor led
  pinMode(ledInPin, OUTPUT);
  digitalWrite(ledInPin, LOW); //set the LED to off
  // initialize serial communication:
  Serial.begin(9600);

}

void loop() {

      buttonState = analogRead(buttonPin);
      if(buttonState>850){
        digitalWrite(ledInPin, HIGH);
      }
      else{
       digitalWrite(ledInPin, LOW);
      }
      Serial.println(buttonState);

}