Circuit Documentation

Summary

This project involves an Arduino Uno interfacing with a 4x4 Keypad, a 16x2 I2C LCD, and a 12V Solenoid Lock via an L298N motor driver. The system is designed to enhance security features for residential door locks by allowing secure access control using a keypad input.

Component List

1. 12V Solenoid Lock

   • Description: An electromechanical lock that operates on 12V.
   • Pins: -, +
   • Purpose: Used to lock and unlock the door.

2. 9V Battery

   • Description: A power source providing 9V.
   • Pins: -, +
   • Purpose: Supplies power to the circuit.

3. 4x4 Keypad (Simulator)

   • Description: A matrix keypad with 4 rows and 4 columns.
   • Pins: R1, C4, R2, C2, R3, R4, C1, C3
   • Purpose: Used for user input to enter the password.

4. 16x2 I2C LCD

   • Description: A 16x2 character LCD with I2C interface.
   • Pins: GND, VCC, SDA, SCL
   • Purpose: Displays messages to the user.

5. L298N DC Motor Driver

   • Description: A dual H-bridge motor driver.
   • Pins: OUT1, OUT2, 12V, GND, 5V, OUT3, OUT4, 5V-ENA-JMP-I, 5V-ENA-JMP-O, +5V-J1, +5V-J2, ENA, IN1, IN2, IN3, IN4, ENB
   • Purpose: Controls the 12V Solenoid Lock.

6. Arduino UNO

   • Description: A microcontroller board based on the ATmega328P.
   • Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0
   • Purpose: Acts as the main controller for the circuit.

Wiring Details

12V Solenoid Lock

• - connected to OUT2 of L298N DC Motor Driver
• + connected to OUT1 of L298N DC Motor Driver

9V Battery

• - connected to GND of L298N DC Motor Driver and GND of Arduino UNO
• + connected to 12V of L298N DC Motor Driver

4x4 Keypad (Simulator)

• R1 connected to D13 of Arduino UNO
• R2 connected to D12 of Arduino UNO
• R3 connected to D11 of Arduino UNO
• R4 connected to D10 of Arduino UNO
• C1 connected to D9 of Arduino UNO
• C2 connected to D8 of Arduino UNO
• C3 connected to D7 of Arduino UNO
• C4 connected to D6 of Arduino UNO

16x2 I2C LCD

• GND connected to GND of Arduino UNO
• VCC connected to 5V of Arduino UNO
• SDA connected to A1 of Arduino UNO
• SCL connected to A2 of Arduino UNO

L298N DC Motor Driver

• 5V connected to Vin of Arduino UNO
• GND connected to GND of Arduino UNO and - of 9V Battery
• IN1 connected to D5 of Arduino UNO
• IN2 connected to D4 of Arduino UNO

Documented Code

/*
 * Project: Assessing the Efficacy of Arduino Uno in Enhancing Security Features
 *          for Residential Door Locks
 * Description: This Arduino sketch interfaces with a 4x4 Keypad, 16x2 I2C LCD, 
 *              and a 12V Solenoid Lock via an L298N motor driver. The system 
 *              allows for secure access control using a keypad input.
 */

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

// LCD setup
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Keypad setup
const byte ROWS = 4; // Four rows
const byte COLS = 4; // Four columns
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
byte rowPins[ROWS] = {13, 12, 11, 10}; // Connect to the row pinouts of the keypad
byte colPins[COLS] = {9, 8, 7, 6}; // Connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// L298N motor driver pins
const int solenoidPin1 = 5; // IN1
const int solenoidPin2 = 4; // IN2

// Password setup
String password = "1234";
String inputPassword = "";

void setup() {
  // Initialize LCD
  lcd.begin();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Enter Password:");

  // Initialize solenoid pins
  pinMode(solenoidPin1, OUTPUT);
  pinMode(solenoidPin2, OUTPUT);
  digitalWrite(solenoidPin1, LOW);
  digitalWrite(solenoidPin2, LOW);
}

void loop() {
  char key = keypad.getKey();
  if (key) {
    lcd.setCursor(inputPassword.length(), 1);
    lcd.print('*');
    inputPassword += key;

    if (inputPassword.length() == password.length()) {
      if (inputPassword == password) {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Access Granted");
        unlockDoor();
      } else {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Access Denied");
        delay(2000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter Password:");
      }
      inputPassword = "";
    }
  }
}

void unlockDoor() {
  digitalWrite(solenoidPin1, HIGH);
  digitalWrite(solenoidPin2, LOW);
  delay(5000); // Keep the door unlocked for 5 seconds
  digitalWrite(solenoidPin1, LOW);
  digitalWrite(solenoidPin2, LOW);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Enter Password:");
}

This code initializes the LCD and keypad, sets up the solenoid lock control pins, and implements a simple password-based access control system. When the correct password is entered, the solenoid lock is activated to unlock the door for 5 seconds.