#include <Keypad.h>

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

byte rows[]{12,11,10,9};
byte cols[]{7,6,5,4};
int tam = sizeof(rows);
Keypad kdp(makeKeymap(keyMap), rows, cols, tam, tam);

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

void loop() {
  char carac = kdp.getKey();
  
  if(carac != NO_KEY)
    Serial.println(carac);
}