โครงงานประตูรหัส              

#include <Keypad.h>

#define RELAY_PIN  A0 // the Arduino pin that controls solenoid lock via relay

#define ROW_NUM    4  // four rows

#define COLUMN_NUM 3  // three columns

char keys[ROW_NUM][COLUMN_NUM] = {

  {'1','2','3'},

  {'4','5','6'},

  {'7','8','9'},

  {'*','0','#'}

};

byte pin_rows[ROW_NUM] = {9, 8, 7, 6}; //connect to the row pinouts of the keypad

byte pin_column[COLUMN_NUM] = {5, 4, 3}; //connect to the column pinouts of the keypad

Keypad keypad = Keypad( makeKeymap(keys), pin_rows, pin_column, ROW_NUM, COLUMN_NUM );

const String password_1 = "1234"; // change your password here

const String password_2 = "56789"; // change your password here

const String password_3 = "901234"; // change your password here

String input_password;

bool unlocked = false; // track if the lock is unlocked

void setup() {

  Serial.begin(9600);

  input_password.reserve(32); // maximum password size is 32, change if needed

  pinMode(RELAY_PIN, OUTPUT); // initialize pin as an output.

  digitalWrite(RELAY_PIN, HIGH); // lock the solenoid lock

}

void loop() {

  char key = keypad.getKey();

  if (key) {

    Serial.println(key);

    if (key == '*') {

      input_password = ""; // reset the input password

    } else if (key == '#') {

      if (input_password == password_1 || input_password == password_2 || input_password == password_3) {

        Serial.println("The password is correct => unlock");

        digitalWrite(RELAY_PIN, LOW);

        unlocked = true; // set unlock status to true

        delay(5000); // wait for 3 seconds

        digitalWrite(RELAY_PIN, HIGH); // lock again after 3 seconds

        unlocked = false; // reset unlock status

      } else {

        Serial.println("The password is incorrect, try again");

      }

      input_password = ""; // reset the input password

    } else {

      input_password += key; // append new character to input password string

    }

  }

}