#include <Keypad.h>

int led=12; 
int buzzer =21;


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 rowPins[ROWS] = {19, 18, 5, 17}; 
byte colPins[COLS] = {16,4,0,2}; 

Keypad mykey = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);
 
void setup()
{
  pinMode(led, OUTPUT);
  pinMode(buzzer, OUTPUT);
}
 
void loop()
{

  char keypressed = mykey.getKey();


  if (keypressed == '1')
  {
    digitalWrite(led, HIGH);
    tone(buzzer,262);
    delay(500);  
    noTone(buzzer);
  }


   if (keypressed == '2')
  {
    digitalWrite(led, LOW);
    tone(buzzer,294); 
    delay(500);
    noTone(buzzer);         
  }
  
 

  if (keypressed == '3')
  {
    tone(buzzer,330);  
    delay(500); 
    noTone(buzzer);    
  }


   if (keypressed == '4')
  {
    tone(buzzer,349);
    delay(500);  
    noTone(buzzer);       
  }

  if (keypressed == '5')
  {
    tone(buzzer,395);  
    delay(500);  
    noTone(buzzer);     
  }


  if (keypressed == '6')
  {
    tone(buzzer,440);
    delay(500);    
    noTone(buzzer);     
  }


  if (keypressed == '7')
  {
    tone(buzzer,494); 
    delay(500);   
    noTone(buzzer);      
  }


  if (keypressed == '8')
  {
    tone(buzzer,523); 
    delay(500);   
    noTone(buzzer);      
  }
 
}