🔐 Password Based Lock System Using 8051 and EEPROM

This project is a password protected lock system made using 8051 microcontroller.
The password is stored in external EEPROM, so it is not lost when power is turned OFF.

The system uses a keypad to enter the password and an LCD to display messages.

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📌 Features

• 4 digit password security
• Password stored in EEPROM (non-volatile memory)
• Change password option
• Buzzer alert for wrong password
• Lock system after 3 wrong attempts
• LCD display for user interface
• Proteus simulation included

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🧰 Components Used

• AT89C51 (8051 Microcontroller)
• 16x2 LCD Display
• 4x4 Matrix Keypad
• 24C02 EEPROM
• Buzzer
• Crystal Oscillator
• Resistors and Capacitors
• Proteus 8 Software

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⚙️ How It Works

1. System shows "ENTER PASS" on LCD.
2. User enters password using keypad.
3. Microcontroller checks password with EEPROM.
4. If correct → Access Granted.
5. If wrong → Buzzer sounds.
6. After 3 wrong tries → System is locked.
7. User can change password using 'D' key.

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▶️ How To Run

1. Open the Proteus file.
2. Load the HEX file in 8051.
3. Run simulation.
4. Enter password using keypad.

Default Password: 2005

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📁 Project Files

• Code folder contains C program
• Proteus folder contains simulation file
• Images folder contains circuit screenshots

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👨‍💻 Author

Ganesh
ECE Student | Embedded Systems Enthusiast

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📜 License

This project is for learning and educational purpose.

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Circuit Diagram

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Working Demo

• Enter 4-digit password
• Press # to submit
• Press D(div symbol) to change password
• After 3 wrong attempts system locks

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Simulation Results

Enter Password

Access Granted

Wrong Password

System Locked

Enter Old Password

Set New Password

Password Updated