#include <Keypad.h>
#include <ezBuzzer.h>

const int BUZZER_PIN =11;
const int ROW_NUM =4;
const inst COLUMN_NUM =4;

char keys [ROW_NUM] [COLUMN_NUM] ={
{'1' , '2' , '3' , 'A' }, 
{ '4' , '5' , '6' , 'B' }, 
{ '7' , '8' , '9' , 'C' }, 
{ '*' , '0' , '#' , 'D' } 
};
byte pin_rows[ROW_NUM]={9, 8, 7, 6};
byte pin_column[COLUMN_NUM] = {5, 4, 3, 2};
Keypad Keypad = keypad(makeKeymap), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );
ezBuzzer buzzer(BUZZER_PIN);

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

}

void loop() {
buzzer loop();
char key = keypad.getKey();

if (ke) {
Serial.print(key);
buzzer.beep(100);
}

}