Smart Arduino Door Lock System With Voice Alert

Smart Arduino Door Lock System is a sophisticated and customizable security solution that enhances access control in both residential and commercial apartments. Combining the versatility of the Arduino platform with essential hardware components like a keypad, servo motor, and DFPlayer Mini, this project provides a secure, interactive, and user-friendly method to manage door access.

Core Features of the Smart Arduino Door Lock System

User Interaction via Keypad
The system features a keypad for entering a numeric password to unlock the door. Advanced functionalities, such as real-time error correction, allow users to delete characters during input, ensuring a smooth and intuitive experience.
Servo Motor-Driven Lock Mechanism
Upon entering the correct password, the Arduino signals a servo motor to rotate and unlock the door. This motorized mechanism is quiet and reliable, reducing wear and tear compared to traditional mechanical locks.
Audio Feedback with DFPlayer Mini
The inclusion of the DFPlayer Mini module enhances the user experience by providing voice alerts or sound effects for various actions, such as successful entry, incorrect password attempts, or password changes. This makes the system reliable and user-friendly, even for individuals unfamiliar with digital locks.
Password Security and Confirmation
Security is paramount, and the system includes a password confirmation process for setting or updating passwords. This prevents accidental errors and ensures intentional changes to security credentials.

With its combination of robust security, ease of use, and adaptability, the Arduino Door Lock System stands out as an ideal solution for anyone looking to upgrade their security system. This system provides peace of mind through innovative technology and thoughtful design, whether for a home, office, or other secure areas.

Must Read Arduino Door Lock System

Project

Circuit Design Using KiCad

Note: WS2812B NeoPixel pin will connect to D13 of Arduino. Not D12 which is mentioned in the diagram.

Components Required

Arduino UNO
4×4 Keypad
LiquidCrystal I2C Display (20×4)
Servo Motor
WS2812B NeoPixel LED Strip (or a single NeoPixel LED)
4 ohm Speaker
Buzzer
DFPlayer Mini MP3 Player Module
1Kohm Resistors
Connecting Wires
5 Volt Power Supply
Breadboard

Circuit Connection

DFPlayer Mini (Audio Player):

Arduino Pins:
- Pin D10 (SoftwareSerial RX) > DFPlayer Mini TX
- Pin D11 (SoftwareSerial TX) > DFPlayer Mini RX
Connected to: DFPlayer Mini (for playing audio feedback)

I2C LCD (20×4 Display):

I2C Interface Pins:
- Arduino A4> LCD SDA
- Arduino A5 > LCD SCL
Connected to: 20×4 I2C LCD Display (for displaying messages)

4×4 Keypad:

Arduino Pins:
- Rows: Pin 9, Pin 8, Pin 7, Pin 6 -> Keypad Rows
- Columns: Pin 5, Pin 4, Pin 3, Pin 2 -> Keypad Columns
Connected to: 4×4 Keypad (for user input)

Servo Motor:

Arduino Pin: A1
Connected to: Servo motor (for controlling the lock/unlock mechanism)

RGB LED (Adafruit Neopixel):

Arduino Pin: D13
Connected to: RGB LED strip (for visual feedback)

PAM8403 Audio Amplifier:

PAM8403 left & right input to DFPlayer Mini SPK1 & SPK2

Speaker:

PAM8403 Audio Amplifier: LOUT+ and LOUT-
Connected to: Speaker (for sound feedback)

Buzzer:

Buzzer positive pin to Arduino D12

Why Choose KiCad for Your PCB Design?

KiCad and PCBWay have partnered to simplify PCB design and manufacturing. Key benefits include:

Seamless Integration: KiCad now directly supports PCBWay’s manufacturing standards, ensuring design compatibility.
Easy Ordering: A dedicated plugin enables one-click file uploads and orders within KiCad.
Community-Driven Enhancements: Continuous improvements are driven by both KiCad’s open-source nature and PCBWay’s community contributions.
Optimized Libraries: KiCad libraries now include components specifically suited for PCBWay manufacturing.
Cost-Effectiveness: KiCad’s free software combines with PCBWay’s affordable manufacturing for a budget-friendly solution.

This partnership simplifies the design-to-production process, making KiCad an excellent choice for efficient PCB development.

How to Design PCBs & Order it from PCBWay

Prototyping is necessary to transition this circuit design into a commercial or shareable product. The PCB editor and its accompanying plugins provide the tools to carry out this prototyping phase effectively.

To begin, locate and click on the “Plugin and Content Manager” within the main KiCad interface. This is typically pointed by a dedicated red arrow.

Next, locate and install the necessary PCB plugin i.e., PCBWay.

In the Plugin Manager interface, use the search field to find “pcbway“
Click “Install” to begin the installation process.
Before closing the window, remember to click “Apply Pending Changes” to finalize the installation.

After installing the PCBWay plugin from the KiCad plugin manager, it’s time to build our PCB prototype from the prototype section.

Smart Arduino Door Lock System PCB Design

The highlighted area using yellow colour shows the menu icons for all plugins I have installed.

Once I’ve placed all components and routed all the tracks, I perform a Design Rule Check (DRC) to ensure the design adheres to all the necessary rules. If no errors are found, I click the PCBWay icon located within the plugin menu.

Download Gerber File

This action saves my design in a ZIP file compatible with PCBWay’s manufacturing process. This ZIP file contains all necessary files for production. Subsequently, the plugin automatically opens the PCBWay ordering page, allowing me to customize the manufacturing settings according to my preferences.

Crucial settings, such as the choice of materials, the number of layers (automatically determined based on your design), panel or individual board fabrication (particularly useful for small-scale projects), and board colour (options include classic green, matte green, yellow, red, purple, blue, black, and white), can be adjusted. However, for this demonstration, I will accept the default settings.

Next, I selected my region and chose my preferred courier service according to delivery speed. While DHL generally offers the fastest shipping, other couriers may provide more economical options depending on your budget and time constraints. On the same page, an estimated total price is displayed for reference.

After carefully reviewing all settings and confirming they meet my requirements, I clicked ‘Save to Cart‘ to proceed to the payment step. This process is simple. However, it’s crucial to double-check that the correct design has been uploaded. The plugin simplifies this by automatically naming the file according to your project name. If your design involves a panel or multiple boards combined into a single design with snap-away tabs, ensure that the ‘Different design in panel’ option is correctly set. This option should match the number of unique designs within the panel.

As indicated, the option is selected, allowing you to proceed to checkout using the button provided. You can pay for this specific order separately by checking the corresponding box. This feature is particularly useful when dealing with multiple versions or orders, although it’s crucial to exercise caution to avoid errors if the designs appear similar. Before proceeding, ensure that all shipping details are accurately filled in. You can easily access and update your shipping information on the ‘My PCBWay‘ page. Please review and confirm your shipping details before proceeding with the checkout process.

After a successful review, you will be redirected to the “Awaiting Payment” section where you can choose any payment option including PCBWay credit.

After 3 to 5 business days, you will receive your prototype for your project.

Other Services They Provide

PCB Fabrication:

PCBWay offers high-quality PCB fabrication with precise processes, including automated DFM checks, UV printing, etching, drilling, plating, solder masking, and silkscreen labeling. Rigorous electrical testing ensures reliability, while a variety of materials and finishes are supported. Rapid prototyping and bulk production are available with quick turnaround times.

Checkout

PCB Assembly

PCBWay provides both SMT and through-hole PCB assembly using advanced automated machinery, reflow soldering, and AOI inspection for accuracy. Services include component sourcing, assembly, and testing, ensuring reliable, ready-to-use PCBs with fast delivery options.

Checkout

CNC Machining & 3D Printing:

PCBWay offers precision CNC machining and 3D printing services, supporting custom prototypes and parts with a variety of materials like metals and plastics. High accuracy, fast turnaround, and quality assurance make it ideal for both industrial and personal projects.

Checkout

OEM & EMS Services:

PCBWay’s OEM and EMS solutions cover the entire product lifecycle, from design and prototyping to manufacturing and assembly. They offer end-to-end services, including supply chain management, quality control, and global shipping, ensuring efficient, reliable product delivery.

Checkout

Project View

System Features Overview

Keypad Input

Users can enter a password using a 4×4 keypad, providing secure and customizable access control.

Password Management

Set a New Password: Press the ‘B’ key, confirm the current password by pressing ‘A’, and enter the new password.
Persistent Storage: Passwords are saved in the EEPROM, ensuring retention even after a power cycle.

Feedback Mechanisms

LCD Display: Provides real-time feedback and instructions to the user.
LED Strip: An Adafruit NeoPixel LED indicates system states with colours.
Speaker: Emits audio tones for alerts and feedback.
DFPlayer Mini: Plays audio files for states like “Door Unlocked,” “Wrong Password,” etc.
Servo Motor: Operates the locking mechanism, moving to unlock or re-lock the door.

Error Handling

The system includes robust error-handling mechanisms, such as error messages for incorrect passwords, invalid operations, and a delete character function to correct input errors.

Password Management Function

To Unlock the Door: Enter the current password and press ‘A’ to unlock. The servo will move to the unlocked position for 5 seconds.

To Set a New Password:

Press ‘B’ to enter the password-setting mode.
Enter the current password and press ‘A’.
Enter the new password and press ‘A’ to confirm.

Error Handling: If the wrong password is entered, the system will display an error, blink the LED in red, beep the buzzer, and play the “Wrong Password” audio.

Audio Feedback System

The DFPlayer Mini module is used in the system to provide real-time audio feedback, enhancing the user experience. Whenever a user action is taken such as entering the correct password, receiving an error message, or confirming a password change, the system will play corresponding voice alerts through a connected 4 ohm speaker. This ensures that users are always aware of their interactions with the door lock system, making it more intuitive and accessible, especially for those unfamiliar with the device.

Audio Files for Audio Feedback

File 1 (Wrong Password):

File 2 (Password Saved):

File 3 (Invalid Length):

File 4 (Door Unlocked):

File 5 (Door Re-Locking):

Copy these audio files into an SD card.

How to Handle Error and Security?

The system includes several error-handling features, such as the delete character function, allowing users to correct input mistakes during password entry. Additionally, the password confirmation process ensures that changes to the password are intentional and correct, preventing accidental updates or unauthorized access. If an incorrect password is entered multiple times, the system can be programmed to trigger an alert or lockout for a certain period to prevent brute-force attacks.

Coding Explanation

The code for the Smart Arduino Door Lock System is structured to manage user input, control hardware components, and provide audio feedback effectively. At its core, the system utilizes various libraries that facilitate interaction with components like the keypad, LCD, DFPlayer Mini, and servo motor.

Key Libraries Used

Keypad Library: Used to decode the 4×4 keypad inputs, allowing user password entry and management.
LiquidCrystal_I2C Library: Enables communication with the I2C LCD for displaying messages and statuses.
Servo Library: Controls the servo motor for locking and unlocking the door.
DFRobotDFPlayerMini Library: Manages audio playback from the DFPlayer Mini module, ensuring clear communication of states via audio prompts.

Source Code

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <Servo.h>
#include <EEPROM.h>
#include <Adafruit_NeoPixel.h>
#include <DFRobotDFPlayerMini.h>
#include <SoftwareSerial.h>

#define maxPasswordLength 4
#define buzzerPin 12
#define servoPin A1
#define ledPin 13       // Use A0 (D14) for LED strip output
#define numPixels 1

SoftwareSerial mySerial(10, 11); // RX, TX for DFPlayer Mini
DFRobotDFPlayerMini dfPlayer;

LiquidCrystal_I2C lcd(0x27, 20, 4);
Servo myServo;
Adafruit_NeoPixel strip = Adafruit_NeoPixel(numPixels, ledPin, NEO_GRB + NEO_KHZ800);

// Keypad setup
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};  // Connect to the row pinouts of the keypad
byte colPins[COLS] = {5, 4, 3, 2};  // Connect to the column pinouts of the keypad
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

String currentPassword = "1234";
String inputPassword = "";
boolean settingPassword = false;
boolean confirmingPassword = false;

void setup() {
  pinMode(buzzerPin, OUTPUT);
  pinMode(ledPin, OUTPUT); // Set A0 as an output pin
  myServo.attach(servoPin);
  strip.begin();
  strip.show();
  
  lcd.init();
  lcd.backlight();
  
  mySerial.begin(9600);
  if (!dfPlayer.begin(mySerial)) {
    lcd.setCursor(0, 0);
    lcd.print("DFPlayer Error");
    while (true);
  }
  
  dfPlayer.volume(30);  // Set volume to a high level
  loadPassword();
}

void loop() {
  char key = keypad.getKey();  // Get the key pressed on the keypad

  if (key == 'B' && !settingPassword && !confirmingPassword) { // Press 'B' to set a new password
    settingPassword = true;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter Old Pass:");
    inputPassword = "";
    return;
  }

  if (settingPassword) {
    if (key == 'A') { // Press 'A' to confirm old password
      if (inputPassword == currentPassword) {
        confirmingPassword = true;
        settingPassword = false;
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter New Pass:");
        inputPassword = "";
      } else {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Wrong Old Pass");
        blinkLED(255, 0, 0, 3, 200);
        beepBuzzer(3, 200);
        playAudio(1); // Play "Wrong Password" audio
        delay(2000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter Old Pass:");
        inputPassword = "";
      }
      return;
    }

    if (key == 'C') { // Press 'C' to clear input
      inputPassword = "";
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Enter Old Pass:");
    } else if (key == 'D') { // Press 'D' to delete the last character
      if (inputPassword.length() > 0) {
        inputPassword.remove(inputPassword.length() - 1);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter Old Pass:");
        lcd.setCursor(0, 1);
        lcd.print(inputPassword);
      }
    } else if (key != NO_KEY) { // Entering the old password
      if (inputPassword.length() < maxPasswordLength) {
        inputPassword += key;
        lcd.setCursor(0, 1);
        lcd.print(inputPassword);
      }
    }
    return;
  }

  if (confirmingPassword) {
    if (key == 'A') { // Press 'A' to confirm the new password
      if (inputPassword.length() == maxPasswordLength) {
        savePassword(inputPassword);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Password Saved");
        blinkLED(0, 255, 0, 3, 200);
        beepBuzzer(3, 200);
        playAudio(2); // Play "Password Saved" audio
        delay(2000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter Password:");
        confirmingPassword = false;
      } else {
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Invalid Length");
        blinkLED(255, 0, 0, 3, 200);
        beepBuzzer(3, 200);
        playAudio(3); // Play "Invalid Length" audio
        delay(1000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter New Pass:");
        lcd.setCursor(0, 1);
        lcd.print(inputPassword);
      }
      return;
    }

    if (key == 'C') { // Press 'C' to clear the new password input
      inputPassword = "";
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Enter New Pass:");
    } else if (key == 'D') { // Press 'D' to delete the last character of the new password
      if (inputPassword.length() > 0) {
        inputPassword.remove(inputPassword.length() - 1);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print("Enter New Pass:");
        lcd.setCursor(0, 1);
        lcd.print(inputPassword);
      }
    } else if (key != NO_KEY) { // Entering the new password
      if (inputPassword.length() < maxPasswordLength) {
        inputPassword += key;
        lcd.setCursor(0, 1);
        lcd.print(inputPassword);
      }
    }
    return;
  }

  // Handle normal password entry
  if (key == 'A') { // Press 'A' to confirm the password
    checkPassword();
  } else if (key == 'C') { // Press 'C' to clear the input
    inputPassword = "";
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter Password:");
  } else if (key == 'D') { // Press 'D' to delete the last character
    if (inputPassword.length() > 0) {
      inputPassword.remove(inputPassword.length() - 1);
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Enter Password:");
      lcd.setCursor(0, 1);
      lcd.print(inputPassword);
    }
  } else if (key != NO_KEY) { // Entering the password
    if (inputPassword.length() < maxPasswordLength) {
      inputPassword += key;
      lcd.setCursor(0, 1);
      lcd.print(inputPassword);
    }
  }
}

void checkPassword() {
  if (inputPassword == currentPassword) {
    myServo.write(90); // Unlock position
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Door Unlocked");
    blinkLED(0, 255, 0, 3, 200);
    beepBuzzer(3, 200);
    playAudio(4); // Play "Door Unlocked" audio
    delay(5000); // Keep the door unlocked for 5 seconds
    myServo.write(0); // Lock position
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Re-Locked");
    playAudio(5); // Play "Re-Locked" audio
    delay(2000);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter Password:");
  } else {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Wrong Password");
    blinkLED(255, 0, 0, 3, 200);
    beepBuzzer(3, 200);
    playAudio(1); // Play "Wrong Password" audio
    delay(1000);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter Password:");
  }
  inputPassword = ""; // Clear the input after checking
}

void loadPassword() {
  char pwd[maxPasswordLength + 1];
  for (int i = 0; i < maxPasswordLength; i++) {
    pwd[i] = EEPROM.read(i);
  }
  pwd[maxPasswordLength] = '\0';
  currentPassword = String(pwd);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Password Loaded");
  delay(1000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Enter Password:");
}

void savePassword(String newPassword) {
  for (int i = 0; i < maxPasswordLength; i++) {
    EEPROM.write(i, newPassword[i]);
  }
  currentPassword = newPassword;
}


void blinkLED(int red, int green, int blue, int times, int delayTime) {
  for (int i = 0; i < times; i++) {
    strip.setPixelColor(0, strip.Color(red, green, blue));
    strip.show();
    delay(delayTime);
    strip.setPixelColor(0, strip.Color(0, 0, 0));
    strip.show();
    delay(delayTime);
  }
}

void beepBuzzer(int times, int delayTime) {
  for (int i = 0; i < times; i++) {
    digitalWrite(buzzerPin, HIGH);
    delay(delayTime);
    digitalWrite(buzzerPin, LOW);
    delay(delayTime);
  }
}

void playAudio(int trackNumber) {
  dfPlayer.play(trackNumber);
}

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#include <Wire.h>

#include <LiquidCrystal_I2C.h>

#include <Keypad.h>

#include <Servo.h>

#include <EEPROM.h>

#include <Adafruit_NeoPixel.h>

#include <DFRobotDFPlayerMini.h>

#include <SoftwareSerial.h>

#define maxPasswordLength 4

#define buzzerPin 12

#define servoPin A1

#define ledPin 13 // Use A0 (D14) for LED strip output

#define numPixels 1

SoftwareSerial mySerial(10, 11); // RX, TX for DFPlayer Mini

DFRobotDFPlayerMini dfPlayer;

LiquidCrystal_I2C lcd(0x27, 20, 4);

Servo myServo;

Adafruit_NeoPixel strip = Adafruit_NeoPixel(numPixels, ledPin, NEO_GRB + NEO_KHZ800);

// Keypad setup

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}; // Connect to the row pinouts of the keypad

byte colPins[COLS] = {5, 4, 3, 2}; // Connect to the column pinouts of the keypad

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

String currentPassword = "1234";

String inputPassword = "";

boolean settingPassword = false;

boolean confirmingPassword = false;

void setup() {

pinMode(buzzerPin, OUTPUT);

pinMode(ledPin, OUTPUT); // Set A0 as an output pin

myServo.attach(servoPin);

strip.begin();

strip.show();

lcd.init();

lcd.backlight();

mySerial.begin(9600);

if (!dfPlayer.begin(mySerial)) {

lcd.setCursor(0, 0);

lcd.print("DFPlayer Error");

while (true);

}

dfPlayer.volume(30); // Set volume to a high level

loadPassword();

}

void loop() {

char key = keypad.getKey(); // Get the key pressed on the keypad

if (key == 'B' && !settingPassword && !confirmingPassword) { // Press 'B' to set a new password

settingPassword = true;

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Old Pass:");

inputPassword = "";

return;

}

if (settingPassword) {

if (key == 'A') { // Press 'A' to confirm old password

if (inputPassword == currentPassword) {

confirmingPassword = true;

settingPassword = false;

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter New Pass:");

inputPassword = "";

} else {

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Wrong Old Pass");

blinkLED(255, 0, 0, 3, 200);

beepBuzzer(3, 200);

playAudio(1); // Play "Wrong Password" audio

delay(2000);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Old Pass:");

inputPassword = "";

}

return;

}

if (key == 'C') { // Press 'C' to clear input

inputPassword = "";

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Old Pass:");

} else if (key == 'D') { // Press 'D' to delete the last character

if (inputPassword.length() > 0) {

inputPassword.remove(inputPassword.length() - 1);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Old Pass:");

lcd.setCursor(0, 1);

lcd.print(inputPassword);

}

} else if (key != NO_KEY) { // Entering the old password

if (inputPassword.length() < maxPasswordLength) {

inputPassword += key;

lcd.setCursor(0, 1);

lcd.print(inputPassword);

}

return;

}

if (confirmingPassword) {

if (key == 'A') { // Press 'A' to confirm the new password

if (inputPassword.length() == maxPasswordLength) {

savePassword(inputPassword);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Password Saved");

blinkLED(0, 255, 0, 3, 200);

beepBuzzer(3, 200);

playAudio(2); // Play "Password Saved" audio

delay(2000);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Password:");

confirmingPassword = false;

} else {

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Invalid Length");

blinkLED(255, 0, 0, 3, 200);

beepBuzzer(3, 200);

playAudio(3); // Play "Invalid Length" audio

delay(1000);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter New Pass:");

lcd.setCursor(0, 1);

lcd.print(inputPassword);

}

return;

}

if (key == 'C') { // Press 'C' to clear the new password input

inputPassword = "";

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter New Pass:");

} else if (key == 'D') { // Press 'D' to delete the last character of the new password

if (inputPassword.length() > 0) {

inputPassword.remove(inputPassword.length() - 1);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter New Pass:");

lcd.setCursor(0, 1);

lcd.print(inputPassword);

}

} else if (key != NO_KEY) { // Entering the new password

if (inputPassword.length() < maxPasswordLength) {

inputPassword += key;

lcd.setCursor(0, 1);

lcd.print(inputPassword);

}

return;

}

// Handle normal password entry

if (key == 'A') { // Press 'A' to confirm the password

checkPassword();

} else if (key == 'C') { // Press 'C' to clear the input

inputPassword = "";

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Password:");

} else if (key == 'D') { // Press 'D' to delete the last character

if (inputPassword.length() > 0) {

inputPassword.remove(inputPassword.length() - 1);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Password:");

lcd.setCursor(0, 1);

lcd.print(inputPassword);

}

} else if (key != NO_KEY) { // Entering the password

if (inputPassword.length() < maxPasswordLength) {

inputPassword += key;

lcd.setCursor(0, 1);

lcd.print(inputPassword);

}

void checkPassword() {

if (inputPassword == currentPassword) {

myServo.write(90); // Unlock position

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Door Unlocked");

blinkLED(0, 255, 0, 3, 200);

beepBuzzer(3, 200);

playAudio(4); // Play "Door Unlocked" audio

delay(5000); // Keep the door unlocked for 5 seconds

myServo.write(0); // Lock position

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Re-Locked");

playAudio(5); // Play "Re-Locked" audio

delay(2000);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Password:");

} else {

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Wrong Password");

blinkLED(255, 0, 0, 3, 200);

beepBuzzer(3, 200);

playAudio(1); // Play "Wrong Password" audio

delay(1000);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Password:");

}

inputPassword = ""; // Clear the input after checking

}

void loadPassword() {

char pwd[maxPasswordLength + 1];

for (int i = 0; i < maxPasswordLength; i++) {

pwd[i] = EEPROM.read(i);

}

pwd[maxPasswordLength] = '\0';

currentPassword = String(pwd);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Password Loaded");

delay(1000);

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("Enter Password:");

}

void savePassword(String newPassword) {

for (int i = 0; i < maxPasswordLength; i++) {

EEPROM.write(i, newPassword[i]);

}

currentPassword = newPassword;

}

void blinkLED(int red, int green, int blue, int times, int delayTime) {

for (int i = 0; i < times; i++) {

strip.setPixelColor(0, strip.Color(red, green, blue));

strip.show();

delay(delayTime);

strip.setPixelColor(0, strip.Color(0, 0, 0));

strip.show();

delay(delayTime);

}

void beepBuzzer(int times, int delayTime) {

for (int i = 0; i < times; i++) {

digitalWrite(buzzerPin, HIGH);

delay(delayTime);

digitalWrite(buzzerPin, LOW);

delay(delayTime);

}

void playAudio(int trackNumber) {

dfPlayer.play(trackNumber);

}

Download Full Source Code

Basic Structure of the Code

The code initializes the libraries and sets up the pins for various components. The setup() function lays the groundwork by configuring the serial communication, initializing the components, and displaying a welcome message on the LCD.

The main loop continuously checks for user input from the keypad, processing commands such as unlocking the door and changing the password. Upon detecting a valid input, the system provides audio or visual feedback, indicating the result of the action taken by the user.

Testing and Calibration

Testing and calibration are crucial phases before the system can be deployed for actual use. This process includes:

Servo Calibration: Adjust the angles and timing in the code to ensure the servo motor correctly aligns with the locking mechanism without jamming or hindering operation.
Input Validation Testing: Attempt various correct and incorrect password inputs to verify that the system accurately recognizes and responds to each scenario.
Audio Feedback Check: Ensure that all audio prompts are played correctly and clearly. Test the responsiveness of the DFPlayer Mini to guarantee that users are receiving prompt feedback when interacting with the system.
User Interaction Simulation: Perform tests as an end user would, including entering passwords, setting new passwords, and triggering error conditions. This helps uncover any potential issues with user input handling or feedback communication.

By rigorously testing each feature and fine-tuning the system, you will enhance the overall reliability of the door lock system, providing a secure and user-friendly experience.

Video Output

Conclusion

The Smart Arduino Door Lock System demonstrates a perfect synergy of hardware and software to create a robust and user-friendly security solution. With the support of PCBWay for professional-grade PCBs and KiCad for circuit design, this project exemplifies how collaboration with leading platforms can drive innovation.

Whether you are a hobbyist or a professional programmer, this project enhances your technical skills and provides a practical application that can be used in real-world scenarios. Embracing this technology ensures that you remain ahead in the evolution of smart security systems, paving the way for more advanced, interconnected security solutions.

Sponsored by PCBWay and KiCad

Core Features of the Smart Arduino Door Lock System

Project

Circuit Design Using KiCad

Components Required

Circuit Connection

Why Choose KiCad for Your PCB Design?

How to Design PCBs & Order it from PCBWay

Other Services They Provide

Project View

System Features Overview

Password Management Function

Audio Feedback System

Audio Files for Audio Feedback

How to Handle Error and Security?

Coding Explanation

Key Libraries Used

Source Code

Basic Structure of the Code

Testing and Calibration

Video Output

Conclusion

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