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!
- 4-digit password authentication
- Input masking using asterisks (
*) - LCD feedback for every step
- Button
*clears the input - Button
#submits the password
| Component | Quantity |
|---|---|
| Arduino Uno R3 | 1 |
| 4x4 Matrix Keypad | 1 |
| 16x2 LCD Display | 1 |
| Potentiometer | 1 |
| Breadboard | 1 |
| Jumper Wires | Several |
| 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 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 |
- LCD displays "Enter Password".
- User presses keys on the keypad.
- Input is masked as
*on LCD. - Press
#to submit. - If password is correct → "Access Granted" If incorrect → "Access Denied"
- Press
*to reset input anytime.
You’ll find the Arduino .ino code in the digital-lock.ino file. It's clean, well-commented, and easy to understand.
💻 Click here to open the project in TinkerCAD
Digital-Lock-System/
├── digital-lock.ino # Arduino code ├── README.md # Project documentation