#include <Keypad.h>

#define R1 23
#define R2 25
#define R3 27
#define R4 29
#define C1 31
#define C2 33
#define C3 35
#define C4 37

const byte ROWS = 4;
const byte COLS = 4;

char keys[ROWS][COLS] = {
 {'1', '2', '3', 'A'},
 {'4', '5', '6', 'B'},
 {'7', '8', '9', 'C'},
 {'*', '0', '#', 'D'}, 
};

byte keypadRowPins[ROWS]= {R1, R2, R3, R4}; // row pins connected to Arduino
byte keypadColPins[COLS]= {C1,C2, C3, C4}; // column pins connected to Arduino

Keypad keypad = Keypad(makeKeymap(keys), keypadRowPins, keypadColPins, ROWS, COLS);

const int buzzerPin = 47;

// BCD IC A (ones digit)
const int bcdA_A = 22;
const int bcdA_B = 24;
const int bcdA_C = 26;
const int bcdA_D = 28;

// BCD IC B (tens digit)
const int bcdB_A = 30;
const int bcdB_B = 32;
const int bcdB_C = 34;
const int bcdB_D = 36;

// BCD IC C (hundreds digit)
const int bcdC_A = 39;
const int bcdC_B = 45;
const int bcdC_C = 43;
const int bcdC_D = 41;

// BCD IC D (thousands digit)
const int bcdD_A = 46;
const int bcdD_B = 48;
const int bcdD_C = 50;
const int bcdD_D = 52;

// Button pins
const int startStopButtonPin = 10;
const int countUpButtonPin = 11;
const int countDownButtonPin = 12;

int counterValue = 0; // stores counter value from 0 - 9999

void setup() {
  Serial.begin(9600);

  pinMode(buzzerPin, OUTPUT);

  // Set pin modes for BCD ICs
  for (int pin = bcdA_A; pin <= bcdD_D; ++pin) {
    pinMode(pin, OUTPUT);
  }
 
  counterValue = 0000;

}

void loop() {

  char key = keypad.getKey();

  if (key !=NO_KEY) { 
  Serial.println(key);
  tone(buzzerPin, 1500, 100);

  }


}

void displayDigit(int digit, int digitA, int digitB, int digitC, int digitD) {
    switch (digit) {
    case 0:
      digitalWrite(digitA, LOW);
      digitalWrite(digitB, LOW);
      digitalWrite(digitC, LOW);
      digitalWrite(digitD, LOW);
      break;

    case 1:
      digitalWrite(digitA, HIGH);
      digitalWrite(digitB, LOW);
      digitalWrite(digitC, LOW);
      digitalWrite(digitD, LOW);
      break;

    case 2:
      digitalWrite(digitA, LOW);
      digitalWrite(digitB, HIGH);
      digitalWrite(digitC, LOW);
      digitalWrite(digitD, LOW);
      break;

    case 3:
      digitalWrite(digitA, HIGH);
      digitalWrite(digitB, HIGH);
      digitalWrite(digitC, LOW);
      digitalWrite(digitD, LOW);
      break;

    case 4:
      digitalWrite(digitA, LOW);
      digitalWrite(digitB, LOW);
      digitalWrite(digitC, HIGH);
      digitalWrite(digitD, LOW);
      break;

    case 5:
      digitalWrite(digitA, HIGH);
      digitalWrite(digitB, LOW);
      digitalWrite(digitC, HIGH);
      digitalWrite(digitD, LOW);
      break;

    case 6:
      digitalWrite(digitA, LOW);
      digitalWrite(digitB, HIGH);
      digitalWrite(digitC, HIGH);
      digitalWrite(digitD, LOW);
      break;

    case 7:
      digitalWrite(digitA, HIGH);
      digitalWrite(digitB, HIGH);
      digitalWrite(digitC, HIGH);
      digitalWrite(digitD, LOW);
      break;

    case 8:
      digitalWrite(digitA, LOW);
      digitalWrite(digitB, LOW);
      digitalWrite(digitC, LOW);
      digitalWrite(digitD, HIGH);
      break;

    case 9:
      digitalWrite(digitA, HIGH);
      digitalWrite(digitB, LOW);
      digitalWrite(digitC, LOW);
      digitalWrite(digitD, HIGH);
      break;

  }
}