8051 HEX KEYPAD TO LCD display

circuit diagram:

software design:

PART1

PART 2

PART3

PART4

PART5

PART6

/* Main.c file generated by New Project wizard
 *
 * Created:   Thu Feb 9 2023
 * Processor: AT89C51RD2
 * Compiler:  Keil for 8051
 */

#include<reg51.h>

#define display_port P2      //Data pins connected to port 2 on microcontroller

sbit rs = P3^2;  //RS pin connected to pin 2 of port 3

sbit rw = P3^3;  // RW pin connected to pin 3 of port 3

sbit e =  P3^4;  //E pin connected to pin 4 of port 3


sbit C4 = P1^0;     // Connecting keypad to Port 1

sbit C3 = P1^1;

sbit C2 = P1^2;

sbit C1 = P1^3;

sbit R4 = P1^4;

sbit R3 = P1^5;

sbit R2 = P1^6;

sbit R1 = P1^7;


void msdelay(unsigned int time)  // Function for creating delay in milliseconds.

{

    unsigned i,j ;

    for(i=0;i<time;i++)    

    for(j=0;j<1275;j++);

}

void lcd_cmd(unsigned char command)  //Function to send command instruction to LCD

{

    display_port = command;

    rs= 0;

    rw=0;

    e=1;

    msdelay(1);

    e=0;

}


void lcd_data(unsigned char disp_data)  //Function to send display data to LCD

{

    display_port = disp_data;

    rs= 1;

    rw=0;

    e=1;

    msdelay(1);

    e=0;

}


 void lcd_init()    //Function to prepare the LCD  and get it ready

{

    lcd_cmd(0x38);  // for using 2 lines and 5X7 matrix of LCD

    msdelay(10);

    lcd_cmd(0x0F);  // turn display ON, cursor blinking

    msdelay(10);

    lcd_cmd(0x01);  //clear screen

    msdelay(10);

    lcd_cmd(0x81);  // bring cursor to position 1 of line 1

    msdelay(10);

}


void row_finder1() //Function for finding the row for column 1

{

R1=R2=R3=R4=1;

C1=C2=C3=C4=0;


if(R1==0)

lcd_data('7');

if(R2==0)

lcd_data('4');

if(R3==0)

lcd_data('1');

if(R4==0)

lcd_data('*');

}


void row_finder2() //Function for finding the row for column 2

{

R1=R2=R3=R4=1;

C1=C2=C3=C4=0;


if(R1==0)

lcd_data('8');

if(R2==0)

lcd_data('5');

if(R3==0)

lcd_data('2');

if(R4==0)

lcd_data('0');

}


void row_finder3() //Function for finding the row for column 3

{

R1=R2=R3=R4=1;

C1=C2=C3=C4=0;


if(R1==0)

lcd_data('9');

if(R2==0)

lcd_data('6');

if(R3==0)

lcd_data('3');

if(R4==0)

lcd_data('#');

}


void row_finder4() //Function for finding the row for column 4

{

R1=R2=R3=R4=1;

C1=C2=C3=C4=0;


if(R1==0)

lcd_data('A');

if(R2==0)

lcd_data('B');

if(R3==0)

lcd_data('C');

if(R4==0)

lcd_data('D');

}


void main()

{

    lcd_init();

    while(1)

    {    

        msdelay(30); 

        C1=C2=C3=C4=1;

          R1=R2=R3=R4=0;

          if(C1==0)

          row_finder1();

          else if(C2==0)

           row_finder2();

           else if(C3==0)

        row_finder3();

        else if(C4==0)

        row_finder4();

    }


}