/*
  Button

  Turns on and off a light emitting diode(LED) connected to digital pin 13,
  when pressing a pushbutton attached to pin 4.

  The circuit:
  - LED attached from pin 13 to ground through 220 ohm resistor
  - pushbutton attached to pin 4 from +5V
  - 10K resistor attached to pin 4 from ground

  - Note: on most Arduinos there is already an LED on the board
    attached to pin 13.
  */

//press the blue button to turn on the LED
//Release the blue button to turn off the LED

#define BUTTON_PIN 4
// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);

}


// the loop function runs over and over again forever
void loop() {
  int value = digitalRead((BUTTON_PIN));
    if (value == HIGH) {
      digitalWrite(LED_BUILTIN, LOW);
    }
    if (value == LOW) {
      digitalWrite(LED_BUILTIN, HIGH);
    }
  }