#include <Keypad.h>
#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Tone.h>

#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

const byte ROW_NUM = 4; //four rows
const byte COL_NUM = 4; //four columns

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

byte pin_rows[ROW_NUM] = {9, 8, 7, 6}; //connect to the row pinouts of the keypad
byte pin_column[COL_NUM] = {5, 4, 3, 2}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad(makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COL_NUM);

Tone buzzer;

void setup() {
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.setTextSize(2); // Increase text size for better visibility
  display.setTextColor(WHITE);
  buzzer.begin(10);
}

void loop() {
  static int countUp = 0;
  char key = keypad.getKey();
  if (key) {
    if (key == '1') {
      if (countUp < 500) {
        countUp++;
        display.clearDisplay(); // Clear display before updating
        display.setCursor(0,0);
        display.println("Count Up: " + String(countUp));
        display.display();
        buzzer.play(NOTE_A4);
        delay(100);
        buzzer.stop();
      } else {
        buzzer.play(NOTE_A4);
      }
    } else if (key == '2') {
      if (countUp > 0) {
        countUp--;
        display.clearDisplay(); // Clear display before updating
        display.setCursor(0,0);
        display.println("Count Down: " + String(countUp));
        display.display();
        buzzer.play(NOTE_A4);
        delay(100);
        buzzer.stop();
      } else {
        buzzer.play(NOTE_A4);
      }
    } else if (key == '0') {
      countUp = 0;
      display.clearDisplay();
      display.setCursor(0,0);
      display.println("Count Up: 0");
      display.display();
      buzzer.stop();
    }
  }
}