#include <Keypad.h>
const byte ROWS = 4; //four rows
const byte COLS = 3; //four columns

#define pinrelay 26

char hexaKeys[ROWS][COLS] = {
  {'1', '2', '3'},
  {'4', '5', '6'},
  {'7', '8', '9'},
  {'*', '0', '#'}
};
byte rowPins[ROWS] = {34, 35, 32, 33}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {25, 26, 27}; //connect to the column pinouts of the keypad

Keypad customKeypad = Keypad( makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS);
String StringVal;
int val, pinkey = 2021;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode (pinrelay, OUTPUT);
digitalWrite(pinrelay, 1);
}

void loop() {
  // put your main code here, to run repeatedly:
char Key = customKeypad.getKey();

  if (Key) {
    if (Key >= '0' && Key <= '9') {
      StringVal += Key;
      Serial.println(StringVal);
    }
    else if (Key == '#') {
      if (StringVal.length() > 0) {
        val = StringVal.toInt();
        Serial.println(val);
        if (val == pinkey){
          Serial.println("Pintu Terbuka");
          digitalWrite (pinrelay, 0);
          delay(2000);
          digitalWrite (pinrelay, 1);
        } else {
          digitalWrite(pinrelay, 1);
          Serial.println("Pin Salah");
        }
        StringVal = "";
      }
    }
    else if (Key == '*') {
      StringVal = "";
    }
  }
}