Keypad interfacing with pic microcontroller and Mikro C

In this tutorials I will show you how to interfacing matrix keypad with PIC16F877A microcontroller. You can watch the flowing video and read the written tutorial below.

Keypad is set of button. It contain digits,symbols&alphabetical letters. It can be 4x4&4x3. 4x3 it means 3 column and 4 row.

4x4 keypad structue below.

In this tutorial I am use Mikro C pro for PIC Compiler for microcontroller programming.

The mikroC PRO for PIC provides a library for working with 4x4 keypad. The library routines can also be used with 4x1, 4x2, or 4x3 keypad.

External Dependencies of Keypad Library

Library Routine

Keypad_Init
Keypad_Key_Press
Keypad_Key_Click

Keypad_Init

Keypad_Key_Press

Keypad_Key_Click

Mikro C Code:

	// keypad module connections
	char keypadPort at PORTD;
	// keypad module connection end
	// Lcd module connections
	sbit LCD_RS at RB0_bit;
	sbit LCD_EN at RB1_bit;
	sbit LCD_D4 at RB2_bit;
	sbit LCD_D5 at RB3_bit;
	sbit LCD_D6 at RB4_bit;
	sbit LCD_D7 at RB5_bit;
	sbit LCD_RS_Direction at TRISB0_bit;
	sbit LCD_EN_Direction at TRISB1_bit;
	sbit LCD_D4_Direction at TRISB2_bit;
	sbit LCD_D5_Direction at TRISB3_bit;
	sbit LCD_D6_Direction at TRISB4_bit;
	sbit LCD_D7_Direction at TRISB5_bit;
	// End Lcd module connections
	void main() {
	Lcd_Init(); // intilize Lcd module
	Keypad_Init(); // intialize keypad module
	Lcd_Cmd(_LCD_CLEAR); // Clear Lcd display
	Lcd_Out(1,3,"WELCOME TO");
	Lcd_Out(2,1, "MINA TECHNOLOGY");
	delay_ms(1000); // 1 second delay
	Lcd_Cmd(_LCD_CLEAR); // Clear Lcd display
	while(1){
	kp = 0 ; // reset kp code variable
	// wait for key to be pressed and realized
	do
	kp = Keypad_Key_Click(); // Store key code in kp variable
	while(!kp);
	// Preper value for output transfrom key it's ASCII value
	switch(kp){
	case 1 : Lcd_Cmd(_LCD_CLEAR); break ; // Clear Lcd display
	case 2 : kp = '0' ; break ; // 0
	case 3 : kp = '='; break ; // =
	case 4 : kp = '+' ; break ; // +
	case 5 : kp = '1' ; break ; // 1
	case 6 : kp = '2' ; break ; //2
	case 7 : kp = '3' ; break ; //3
	case 8 : kp = '-' ; break ; // -
	case 9 : kp = '4' ; break ; //4
	case 10 : kp = '5' ; break ; // 5
	case 11 : kp = '6' ; break ; // 6
	case 12 : kp = '' ; break ; //
	case 13 : kp = '7' ; break ; // 7
	case 14 : kp = '8' ; break ; // 8
	case 15 : kp = '9' ; break ; // 9
	case 16 : kp = '/' ; break ; // '/'
	}
	Lcd_Chr_Cp(kp);
	}

	}