#include <Keypad.h>

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] = {9, 8, 7, 6};
byte colPins[COLS] = {5, 4, 3, 2};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

const int greenLED = 12;
const int redLED    = 13;

String correctCode = "1234"; 
String inputCode = "";

void setup() {
  pinMode(greenLED, OUTPUT);
  pinMode(redLED, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    if (key == '#') {
      if (inputCode == correctCode) {
		open();  
      } 
      inputCode = "";
    }else if (key == '*') {
		close();
    	inputCode = "";
    } else {
      inputCode += key;
      Serial.print("Code: ");
      Serial.println(inputCode);
    }
  }
}

void open(){
	digitalWrite(greenLED, HIGH);
   	digitalWrite(redLED, LOW);
}

void close(){
    digitalWrite(redLED, HIGH);
    digitalWrite(greenLED, LOW);	
}