A microcontroller-based PIN-code lock system implemented on the HCS12 Dragon Board. This project uses a 4x4 keypad, an LCD screen, RGB LEDs, and a piezo speaker to create a simple digital security system with visual and audio feedback.
🛠 Built for ECE 3731: Microprocessors and Embedded Systems — Fall 2023
👨💻 Team: Devin Pen, Shuban Srikantha, Anthony D’Alfonso, Henry Chen
🎓 University of Michigan–Dearborn
This embedded system allows a user to:
- Set a 4-digit PIN using the keypad
- Re-enter the PIN to authenticate
- Receive visual and auditory feedback based on input
- LCD displays “LOGGED IN!”
- Green LED lights up
- LCD displays “SYSTEM LOCKED!”
- Red LED lights up
- Piezo speaker sounds an alarm
- HCS12 Dragon Board (MC9S12 MCU)
- 4x4 Keypad
- LCD display (2x16)
- RGB LEDs
- Piezo buzzer
- Laptop
- Programmed in Assembly using CodeWarrior IDE
- LCD interface for display output
- Manual keypad scanning via 4x4 matrix logic
- Use of branching and jump conditions to validate input
- Interrupt-driven audio output using the piezo speaker
Testing focused on:
- Verifying LCD messages
- Capturing keypad input reliably
- Matching entered PINs to the stored value
- Proper color output from LEDs
- Generating alarm frequency on buzzer
This project gave our team hands-on experience with embedded design, low-level programming, user interface elements, microcontrollers, firmware, and real-time input handling. We successfully demonstrated the system functioning as expected under all input scenarios.