/*
references: Lesson_23, Lesson_17
*/
#include <Keypad.h>
#include <LiquidCrystal.h>
 

// set up buzzer
const int BUZZER = 21;


//set up keypad
const byte ROWS = 4;
const byte COLS = 4;
char hexaKeys[ROWS][COLS] = 
{
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {13, 12, 11, 10};
byte colPins[COLS] = {9, 8, 7, 6};
Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 


//set up lcd
LiquidCrystal lcd(19, 18, 14, 15, 16, 17);   
/*
 * LCD RS pin to digital pin 19
 * LCD Enable pin to digital pin 18
 * LCD D4 pin to digital pin 14
 * LCD D5 pin to digital pin 15
 * LCD D6 pin to digital pin 16
 * LCD D7 pin to digital pin 17
 * LCD R/W pin to ground
 * LCD VSS pin to ground
 * LCD VCC pin to 5V
*/
 

//  setup methods
void setUpLCD() {
  lcd.begin(16, 2);
  lcd.clear();
}

void setUpBuzzer() {
  pinMode(BUZZER, OUTPUT);
}

void startMonitoring() {
  Serial.begin(9600);
}
 

// main methods
void setup() {
  setUpBuzzer();
  startMonitoring();
  setUpLCD();
  delay(1000);
}
   
void loop() {
  char customKey = customKeypad.getKey(); 
  if (customKey) {
    PlayTone();
    Serial.println(customKey);
    HandleButtonPress(customKey);
  }
}


// helper methods
void HandleButtonPress(char customKey) {
    if(!CheckAndRunABC(customKey)) lcd.print(customKey);
}

bool CheckAndRunABC(char customKey) {
  switch(customKey) {
    case 'C':
      lcd.clear();
      return true;
    case 'B':
      lcd.noDisplay();
      return true;
    case 'A':
      lcd.display();
      return true;
    default:
      return false;
  }
}

void PlayTone() {
    tone(BUZZER, 500, 500);
}