// #include <LiquidCrystal.h> //Header file for LCD from https://www.arduino.cc/en/Reference/LiquidCrystal
#include <Keypad.h> //Header file for Keypad from https://github.com/Chris--A/Keypad


#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2); 



const byte ROWS = 4; // Four rows
const byte COLS = 4; // Three columns

// Define the Keymap
char keys[ROWS][COLS] = {

  {'1','2','3','A'},

  {'4','5','6','B'},

  {'7','8','9','C'},

  {'*','0','#','D'}

};

byte rowPins[ROWS] = { 9, 8, 7, 6 };// Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins.
byte colPins[COLS] = { 5, 4 , 3, 2 }; // Connect keypad COL0, COL1 and COL2 to these Arduino pins.

Keypad kpd = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS ); //  Create the Keypad

// const int rs = 8, en = 9, d4 = 10, d5 = 11, d6 = 12, d7 = 13; //Pins to which LCD is connected
// LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

//  long Num1,Num2,Number;

//  char key,action;
//  boolean result = false;
 

char key ;


void setup() {
  lcd.init();                      // initialize the lcd 
  lcd.backlight();             //turn ON backlight


// Print a message to the LCD.
  lcd.begin(16, 2); //We are using a 16*2 LCD display

  lcd.setCursor(0,0 ); 
  lcd.print("Hello & Welcome"); //Display a intro message


  // lcd.setCursor(0, 1);   // set the cursor to column 0, line 1
  // lcd.print("-CircuitDigest"); //Display a intro message 


   delay(2000); //Wait for display to show info

    lcd.clear(); //Then clean it
}

void loop() {



 key = kpd.getKey(); //storing pressed key value in a char

 
lcd.setCursor(0, 0);   // set the cursor to column 0, line 1
lcd.print("Enter* for Satrt"); 

lcd.setCursor(0, 1);   // set the cursor to column 0, line 1
lcd.print("Enter# for Set"); 



switch (key) {

case '*' :

lcd.clear(); //Then clean it
lcd.setCursor(6, 0);   // set the cursor to column 0, line 1
lcd.print("Hello"); 
delay (2000);



break ;





case '#' :

lcd.clear(); //Then clean it
lcd.setCursor(5, 0);   // set the cursor to column 0, line 1
lcd.print("Goodbye"); 
delay (2000);


break ;



}






  
}
  
  // {
// key = kpd.getKey(); //storing pressed key value in a char

// if (key!=NO_KEY)
// DetectButtons();

// if (result==true)
// CalculateResult();

// DisplayResult();   
// }

// void DetectButtons()
// { 
//      lcd.clear(); //Then clean it
//     if (key=='*') //If cancel Button is pressed
//     {Serial.println ("Button Cancel"); Number=Num1=Num2=0; result=false;}
    
//      if (key == '1') //If Button 1 is pressed
//     {Serial.println ("Button 1"); 
//     if (Number==0)
//     Number=1;
//     else
//     Number = (Number*10) + 1; //Pressed twice
//     }
    
//      if (key == '4') //If Button 4 is pressed
//     {Serial.println ("Button 4"); 
//     if (Number==0)
//     Number=4;
//     else
//     Number = (Number*10) + 4; //Pressed twice
//     }
    
//      if (key == '7') //If Button 7 is pressed
//     {Serial.println ("Button 7");
//     if (Number==0)
//     Number=7;
//     else
//     Number = (Number*10) + 7; //Pressed twice
//     } 
  

//     if (key == '0')
//     {Serial.println ("Button 0"); //Button 0 is Pressed
//     if (Number==0)
//     Number=0;
//     else
//     Number = (Number*10) + 0; //Pressed twice
//     }
    
//      if (key == '2') //Button 2 is Pressed
//     {Serial.println ("Button 2"); 
//      if (Number==0)
//     Number=2;
//     else
//     Number = (Number*10) + 2; //Pressed twice
//     }
    
//      if (key == '5')
//     {Serial.println ("Button 5"); 
//      if (Number==0)
//     Number=5;
//     else
//     Number = (Number*10) + 5; //Pressed twice
//     }
    
//      if (key == '8')
//     {Serial.println ("Button 8"); 
//      if (Number==0)
//     Number=8;
//     else
//     Number = (Number*10) + 8; //Pressed twice
//     }   
  

//     if (key == '#')
//     {Serial.println ("Button Equal"); 
//     Num2=Number;
//     result = true;
//     }
    
//      if (key == '3')
//     {Serial.println ("Button 3"); 
//      if (Number==0)
//     Number=3;
//     else
//     Number = (Number*10) + 3; //Pressed twice
//     }
    
//      if (key == '6')
//     {Serial.println ("Button 6"); 
//     if (Number==0)
//     Number=6;
//     else
//     Number = (Number*10) + 6; //Pressed twice
//     }
    
//      if (key == '9')
//     {Serial.println ("Button 9");
//     if (Number==0)
//     Number=9;
//     else
//     Number = (Number*10) + 9; //Pressed twice
//     }  

//       if (key == 'A' || key == 'B' || key == 'C' || key == 'D') //Detecting Buttons on Column 4
//   {
//     Num1 = Number;    
//     Number =0;
//     if (key == 'A')
//     {Serial.println ("Addition"); action = '+';}
//      if (key == 'B')
//     {Serial.println ("Subtraction"); action = '-'; }
//      if (key == 'C')
//     {Serial.println ("Multiplication"); action = '*';}
//      if (key == 'D')
//     {Serial.println ("Devesion"); action = '/';}  

//     delay(100);
//   }
  
// }

// void CalculateResult()
// {
//   if (action=='+')
//     Number = Num1+Num2;

//   if (action=='-')
//     Number = Num1-Num2;

//   if (action=='*')
//     Number = Num1*Num2;

//   if (action=='/')
//     Number = Num1/Num2; 
// }

// void DisplayResult()
// {
//   lcd.setCursor(0, 0);   // set the cursor to column 0, line 1
//   lcd.print(Num1); lcd.print(action); lcd.print(Num2); 
  
//   if (result==true)
//   {lcd.print(" ="); lcd.print(Number);} //Display the result
  
//   lcd.setCursor(0, 1);   // set the cursor to column 0, line 1
//   lcd.print(Number); //Display the result
// }