🔐 Digital Lock System with Keypad and LCD

This is a simple Digital Password Lock System built using Arduino, a 4x4 Keypad, and a 16x2 LCD display. The system prompts users to enter a password, masks the input for privacy, and validates it. If the password matches, access is granted; otherwise, access is denied.

✅ Built and tested using TinkerCAD Circuits – no hardware required!

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🔧 Features

• 4-digit password authentication
• Input masking using asterisks (*)
• LCD feedback for every step
• Button * clears the input
• Button # submits the password

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🧰 Components Used (Virtual via TinkerCAD)

Component	Quantity
Arduino Uno R3	1
4x4 Matrix Keypad	1
16x2 LCD Display	1
Potentiometer	1
Breadboard	1
Jumper Wires	Several

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🔌 Circuit Wiring (Based on TinkerCAD Layout)

LCD to Arduino

LCD Pin	Arduino Pin
RS	7
EN	6
D4	5
D5	4
D6	3
D7	2
VSS	GND
VDD	5V
VO	Middle pin of potentiometer (others to 5V and GND)
RW	GND
A	5V (Backlight Anode)
K	GND (Backlight Cathode)

Keypad to Arduino

Keypad Pin	Arduino Pin
Pin 1	9
Pin 2	8
Pin 3	A3
Pin 4	A2
Pin 5	A1
Pin 6	A0
Pin 7	13
Pin 8	12

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🧠 Logic Flow

1. LCD displays "Enter Password".
2. User presses keys on the keypad.
3. Input is masked as * on LCD.
4. Press # to submit.
5. If password is correct → "Access Granted" If incorrect → "Access Denied"
6. Press * to reset input anytime.

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💻 Code

You’ll find the Arduino .ino code in the digital-lock.ino file. It's clean, well-commented, and easy to understand.

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🧪 Simulate it Now!

💻 Click here to open the project in TinkerCAD

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📁 Project Structure

Digital-Lock-System/
├── digital-lock.ino        # Arduino code  
├── README.md               # Project documentation