#include <Keypad.h>
const uint8_t ROWS = 4;
const uint8_t COLS = 4;
char keys1[ROWS][COLS] = {
  { 'Q', 'W', 'E', 'R' },
  { 'A', 'S', 'D', 'F' },
  { 'Z', 'X', 'C', 'V' },
  { '1', '2', '3', '4' }
};
char keys2[ROWS][COLS] = {
  { 'T', 'Y', 'U', 'I' },
  { 'G', 'H', 'J', 'K' },
  { 'B', 'N', 'M', 'L' },
  { '0', ' ', 'O', 'P' }
};
uint8_t colPins1[COLS] = { 9 , 8 , 7 , 6 };
uint8_t rowPins1[ROWS] = { 13 , 12 , 11 , 10 };
uint8_t colPins2[COLS] = { 17 , 16 , 15 , 14 };
uint8_t rowPins2[ROWS] = { 21 , 20 , 19 , 18 };
Keypad keypad1 = Keypad(makeKeymap(keys1), rowPins1, colPins1, ROWS, COLS);
Keypad keypad2 = Keypad(makeKeymap(keys2), rowPins2, colPins2, ROWS, COLS);
void setup() {
  Serial.begin(9600);
}
void loop() {
  char key1 = keypad1.getKey();
  if (key1 != NO_KEY) {
    Serial.print(key1);
  }
  char key2 = keypad2.getKey();
  if (key2 != NO_KEY){
    Serial.print(key2);
  }
}