/*
  State change detection (edge detection)

  Often, you don't need to know the state of a digital input all the time, but
  you just need to know when the input changes from one state to another.
  For example, you want to know when a button goes from OFF to ON. This is called
  state change detection, or edge detection.

  This example shows how to detect when a button or button changes from off to on
  and on to off.

  The circuit:
  - pushbutton attached to pin 2 from +5V
  - 10 kilohm resistor attached to pin 2 from ground
  - LED attached from pin 13 to ground through 220 ohm resistor (or use the
    built-in LED on most Arduino boards)

  created  27 Sep 2005
  modified 30 Aug 2011
  by Tom Igoe

  This example code is in the public domain.

  https://www.arduino.cc/en/Tutorial/BuiltInExamples/StateChangeDetection
*/
/* music */
#define BUZZER_PIN 9

/*
int melody[] = {
  REST, REST, REST, REST, NOTE_E4, NOTE_A4, NOTE_C5,
  
  NOTE_B4, NOTE_A4, NOTE_C5, NOTE_A4, NOTE_B4, NOTE_A4, NOTE_F4, NOTE_G4,
  NOTE_E4, NOTE_E4, NOTE_A4, NOTE_C5,
  NOTE_B4, NOTE_A4, NOTE_C5, NOTE_A4, NOTE_C5, NOTE_A4, NOTE_E4, NOTE_DS4,

  NOTE_D4, NOTE_D4, NOTE_F4, NOTE_GS4,
  NOTE_B4, NOTE_D4, NOTE_F4, NOTE_GS4,
  NOTE_A4, NOTE_C4, NOTE_C4, NOTE_G4,
  NOTE_F4, NOTE_E4, NOTE_G4, NOTE_F4, NOTE_F4, NOTE_E4, NOTE_E4, NOTE_GS4,

  NOTE_A4, REST, NOTE_A4, NOTE_A4, NOTE_GS4,
  NOTE_G4, NOTE_B4, NOTE_A4, NOTE_F4,
  NOTE_E4, NOTE_E4, NOTE_G4, NOTE_E4,
  NOTE_D4, NOTE_D4, NOTE_D4, NOTE_F4, NOTE_DS4,

  NOTE_E4, REST, NOTE_E4, NOTE_A4, NOTE_C5,

  //repeat
  NOTE_B4, NOTE_A4, NOTE_C5, NOTE_A4, NOTE_B4, NOTE_A4, NOTE_F4, NOTE_G4,
  NOTE_E4, NOTE_E4, NOTE_A4, NOTE_C5,
  NOTE_B4, NOTE_A4, NOTE_C5, NOTE_A4, NOTE_C5, NOTE_A4, NOTE_E4, NOTE_DS4,

  NOTE_D4, NOTE_D4, NOTE_F4, NOTE_GS4,
  NOTE_B4, NOTE_D4, NOTE_F4, NOTE_GS4,
  NOTE_A4, NOTE_C4, NOTE_C4, NOTE_G4,
  NOTE_F4, NOTE_E4, NOTE_G4, NOTE_F4, NOTE_F4, NOTE_E4, NOTE_E4, NOTE_GS4,

  NOTE_A4, REST, NOTE_A4, NOTE_A4, NOTE_GS4,
  NOTE_G4, NOTE_B4, NOTE_A4, NOTE_F4,
  NOTE_E4, NOTE_E4, NOTE_G4, NOTE_E4,
  NOTE_D4, NOTE_D4, NOTE_D4, NOTE_F4, NOTE_DS4,

  NOTE_E4
};
*/
int durations[] = {
  4, 8, 8, 8, 8, 8, 8,
  8, 8, 8, 8, 8, 8, 8, 8,
  2, 8, 8, 8,
  8, 8, 8, 8, 8, 8, 8, 8,

  2, 8, 8, 8,
  2, 8, 8, 8,
  2, 8, 8, 8,
  8, 8, 8, 8, 8, 8, 8, 8,

  2, 8, 8, 8, 8,
  2, 8, 8, 8,
  2, 8, 8, 8,
  2, 8, 8, 8, 8,

  2, 8, 8, 8, 8,

  //repeats
  8, 8, 8, 8, 8, 8, 8, 8,
  2, 8, 8, 8,
  8, 8, 8, 8, 8, 8, 8, 8,

  2, 8, 8, 8,
  2, 8, 8, 8,
  2, 8, 8, 8,
  8, 8, 8, 8, 8, 8, 8, 8,

  2, 8, 8, 8, 8,
  2, 8, 8, 8,
  2, 8, 8, 8,
  2, 8, 8, 8, 8,

  2
};
/*music*/
// this constant won't change:
const int buttonPin = 2;  // the pin that the pushbutton is attached to
const int ledPin = 13;    // the pin that the LED is attached to

// Variables will change:
int buttonPushCounter = 0;  // counter for the number of button presses
int buttonState = 0;        // current state of the button
int lastButtonState = 0;    // previous state of the button

void setup() {
  // initialize the button pin as a input:
  pinMode(buttonPin, INPUT);
  // initialize the LED as an output:
  pinMode(ledPin, OUTPUT);
  // initialize serial communication:
  Serial.begin(9600);
}


void loop() {
  // read the pushbutton input pin:
  buttonState = digitalRead(buttonPin);

  // compare the buttonState to its previous state
  if (buttonState != lastButtonState) {
    // if the state has changed, increment the counter
    if (buttonState == HIGH) {
      // if the current state is HIGH then the button went from off to on:
      buttonPushCounter++;
      Serial.println("on");
      Serial.print("number of button pushes: ");
      Serial.println(buttonPushCounter);
    } else {
      // if the current state is LOW then the button went from on to off:
      Serial.println("off");
    }
    // Delay a little bit to avoid bouncing
    delay(50);
  }
  // save the current state as the last state, for next time through the loop
  lastButtonState = buttonState;


  // turns on the LED every four button pushes by checking the modulo of the
  // button push counter. the modulo function gives you the remainder of the
  // division of two numbers:
  if (buttonPushCounter % 4 == 0) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }
}