💡 4x3 Matrix Keypad Interface using PIC16F877A

🔧 Project Overview

This project demonstrates interfacing a 4x3 matrix keypad with a PIC16F877A microcontroller and displaying pressed keys on a 16x2 LCD.

• Keypad rows connected to RB4-RB7
• Keypad columns connected to RB0-RB2
• LCD data connected to PORTC
• LCD control pins connected to RD0-RD2

When a key is pressed, the corresponding character appears on the LCD.

⚙️ Hardware & Software Requirements

Hardware:

• PIC16F877A Microcontroller
• 16x2 LCD Display
• 4x3 Matrix Keypad
• Resistors (for pull-up/pull-down if required)
• Breadboard / Proteus simulation board
• Connecting wires

Software:

• MPLAB X IDE
• XC8 Compiler
• Proteus 8 Professional (for simulation)

🧩 Proteus Circuit Setup

Controller: PIC16F877A

Oscillator: 20 MHz Crystal (pins 13 & 14)

LCD: Data → PORTC, RS→RD0, RW→RD1, EN→RD2

Keypad: Rows → RB4-RB7, Columns → RB0-RB2

Power: +5V to VDD, GND to VSS

▶️ Simulation Steps

Open Proteus_Design.pdsprj in Proteus 8.

Load the compiled .hex file from MPLAB X.

Run simulation — press keys on the keypad and see them displayed on the LCD.

📸 Output

LCD displays the corresponding pressed key:

KEYPAD: <pressed_key>

🧰 Future Expansion Ideas

Implement password entry or access control.

Combine with buzzer/relay for alarms.

Scroll multiple characters or messages on LCD.