Untitled

// music
int songState = 0;

int melody[] = {
  NOTE_F4, NOTE_E4, NOTE_D4, NOTE_CS4,
  NOTE_C4, NOTE_B3, NOTE_AS3, NOTE_A3,
  NOTE_G3, NOTE_A3, NOTE_AS3, NOTE_A3, 
  NOTE_G3, NOTE_C4, 0, 

  NOTE_C4, NOTE_A3, NOTE_A3, NOTE_A3,
  NOTE_GS3, NOTE_A3, NOTE_F4, NOTE_C4, 
  NOTE_C4, NOTE_A3, NOTE_AS3, NOTE_AS3, 
  NOTE_AS3, NOTE_C4, NOTE_D4, 0, 

  NOTE_AS3, NOTE_G3, NOTE_G3, NOTE_G3,
  NOTE_FS3, NOTE_G3, NOTE_E4, NOTE_D4, 
  NOTE_D4, NOTE_AS3, NOTE_A3, NOTE_A3, 
  NOTE_A3, NOTE_AS3, NOTE_C4, 0,

  NOTE_C4, NOTE_A3, NOTE_A3, NOTE_A3,
  NOTE_GS3, NOTE_A3, NOTE_A4, NOTE_F4, 
  NOTE_F4, NOTE_C4, NOTE_B3, NOTE_G4, 
  NOTE_G4, NOTE_G4, NOTE_G4, 0,

  NOTE_G4, NOTE_E4, NOTE_G4, NOTE_G4,
  NOTE_FS4, NOTE_G4, NOTE_D4, NOTE_G4, 
  NOTE_G4, NOTE_FS4, NOTE_G4, NOTE_C4, 
  NOTE_B3, NOTE_C4, NOTE_B3, NOTE_C4, 0
};

int tempo[] = {
  8, 16, 8, 16,
  8, 16, 8, 16,
  16, 16, 16, 8,
  16, 8, 3,

  12, 16, 16, 16,
  8, 16, 8, 16,
  8, 16, 8, 16,
  8, 16, 4, 12,

  12, 16, 16, 16,
  8, 16, 8, 16,
  8, 16, 8, 16,
  8, 16, 4, 12,

  12, 16, 16, 16,
  8, 16, 8, 16,
  8, 16, 8, 16,
  8, 16, 4, 16, 

  12, 17, 17, 17,
  8, 12, 17, 17, 
  17, 8, 16, 8,
  16, 8, 16, 8, 1 
};

// non blocking setup
// free play
unsigned long previousMillis1 = 0; // time words last changed
const long interval1 = 1500; // interval between changing

// music
unsigned long previousMillis2 = 0; // time last changed
const long interval2 = 100; // interval between notes

int displayStatus = 0; // keep track of what's displayed
int mode = 0; // keep track of game mode -- change to 0 or 1 for different modes

bool countdown = false;

unsigned long previousMillis3 = 0; // time last changed
const long interval3 = 1000; // interval between countdown
int count = 20; // challenge mode timer

const int buzzerAnthony = 10; 
const int metalAnthony = 2;

void setup() { 
  // put your setup code here, to run once:
  pinMode(metalAnthony, INPUT); // setup circuit
  pinMode(buzzerAnthony, OUTPUT); // setup buzzer 
}

void buzz(int targetPin, long frequency, long length) {
  tone(targetPin, frequency, length);
  delay(length);    
  noTone(targetPin);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(mode == 0) {
    // challenge mode
    if(digitalRead(2) == HIGH) {
      delay(25);
      if(digitalRead(2) == HIGH) {
        countdown = true; // stop the countdown
      }
      else {
        countdown = false; // stop the countdown
      }
    }
    if(countdown) {
      showCountdown(); // advance countdown
    }
  }
  else {
    // free play
    toggleFreePlay(); 
  }
  if(digitalRead(metalAnthony) == HIGH) {
    buzz(buzzerAnthony, 1000, 500);
  }
  else {
    noTone(buzzerAnthony);
  }
}

void showNumber(int number) {
  // show numbers (maximum 99) on display
  _display->display(0, 25); // write - to segment 1
  _display->display(3, 25); // write - to segment 4 

  // write number to middle of display
  if(number == 10) {
    _display->display(1,1);
    _display->display(2,0);
  }
  else if(number > 9) {
    _display->display(1,1);
    int newVal = number - 10;
    _display->display(2, newVal);
  }
  else {
    _display->display(1,0);
    _display->display(2,number);
  }
}

void toggleFreePlay() {
  // scroll between words without blocking
  unsigned long currentMillis = millis(); // current time
  if (currentMillis - previousMillis1 >= interval1) {
    previousMillis1 = currentMillis;
    if(displayStatus == 1) 
      showPlay();
    else
      showFree();
  }
}

void showPlay() {
  // write "PLAY" to the display
  _display->display(0, 21); // write P to segment 1
  _display->display(1, 18); // write L to segment 2
  _display->display(2, 10); // write A to segment 3
  _display->display(3, 4); // write Y to segment 4
  displayStatus = 2;
}

void showFree() {
  // write "Free" to the display
  _display->display(0, 15); // write F to segment 1
  _display->display(1, 23); // write r to segment 2
  _display->display(2, 14); // write E to segment 3
  _display->display(3, 14); // write E to segment 4
  displayStatus = 1;
}

void showCountdown() {
  // show countdown on display
  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis3 >= interval3) {
    previousMillis3 = currentMillis;
    showNumber(count); // show countdown
   count--; // decrease countdown
if(count == 0) {
  countdown = false; // stop countdown when finished
}
}
}


// CHANGES
// - Moved the `buzzer()` and `tester()` functions outside of the `buzz()` function, 
//   and removed the `buzzer()` function altogether since it was not being used.
// - Removed the `buzz1()` and `buzz2()` functions since they were not being used.
// - Added code to the `loop()` function to check if the metal ring is touching the 
//   electrical wire, and if so, to buzz the buzzer.
// - Removed the `previousButtonState` variable and instead checked the state of the 
//   metal ring in the `loop()` function directly.
// - Updated the pin numbers used for the metal ring and buzzer to match the pin 
//   numbers in the `setup()` function.