doorlock.c

// Inspired from https://github.com/kmhmubin/Password-based-doorlock-system-in-8051-microprocessor

// password based door lock system in 8051 microprocessor

#include <reg51.h>

// connected pins
// keypad rows
sbit keyrow1 = P2 ^ 0;
sbit keyrow2 = P2 ^ 1;
sbit keyrow3 = P2 ^ 2;
sbit keyrow4 = P2 ^ 3;
// keypad column
sbit keycolumn1 = P3 ^ 0;
sbit keycolumn2 = P3 ^ 1;
sbit keycolumn3 = P3 ^ 2;

// motor pins
sbit motorpin1 = P3 ^ 3;
sbit motorpin2 = P3 ^ 4;

// led pins
sbit rs = P3 ^ 5;
sbit rw = P3 ^ 6;
sbit en = P3 ^ 7;

// functions
void lcdcmd(unsigned char);
void lcddat(unsigned char);
void lcddisplay(unsigned char *q);
char keypad();
void check();
void delay(unsigned int);
unsigned char pin[] = {"12345"};
unsigned char Epin[5];

// main function
void main()
{
    lcdcmd(0x0F); // decimal value: 15
    lcdcmd(0x38); // decimal value: 56
    lcdcmd(0x01); // decimal value: 1

    while (1)
    {
        unsigned int i = 0;
        lcdcmd(0x80); // decimal value: 128
        lcddisplay("ENTER PIN NUMBER");
        delay(1000);
        lcdcmd(0xc0); // decimal value: 192
        while (pin[i] != '\0')
        {
            Epin[i] = keypad();
            delay(1000);
            i++;
        }
        check();
    }
}

// delay function
void delay(unsigned int j)
{
    int a, b;
    for (a = 0; a < j; a++)
    {
        for (b = 0; b < 10; b++)
            ;
    }
}

// lcd commands functions
void lcdcmd(unsigned char A)
{
    P1 = A;
    rs = 0;
    rw = 0;
    en = 1;
    delay(1000);
    en = 0;
}

// lcd data function

void lcddat(unsigned char i)
{
    P1 = i;
    rs = 1;
    rw = 0;
    en = 1;
    delay(1000);
    en = 0;
}

// lcd display charecters function

void lcddisplay(unsigned char *q)
{
    int k;
    for (k = 0; q[k] != '\0'; k++)
    {
        lcddat(q[k]);
    }
    delay(10000);
}

// assign keypad character value function

char keypad()
{
    int x = 0;
    while (x == 0)
    {
        // assign values for first row
        keyrow1 = 0;
        keyrow2 = 1;
        keyrow3 = 1;
        keyrow4 = 1;
        if (keycolumn1 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '1';
        }
        if (keycolumn2 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '2';
        }
        if (keycolumn3 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '3';
        }
        // assign values for second row
        keyrow1 = 1;
        keyrow2 = 0;
        keyrow3 = 1;
        keyrow4 = 1;

        if (keycolumn1 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '4';
        }
        if (keycolumn2 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '5';
        }
        if (keycolumn3 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '6';
        }

        // assign values for third row
        keyrow1 = 1;
        keyrow2 = 1;
        keyrow3 = 0;
        keyrow4 = 1;
        if (keycolumn1 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '7';
        }
        if (keycolumn2 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '8';
        }
        if (keycolumn3 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '9';
        }

        // assign values for forth row
        keyrow1 = 1;
        keyrow2 = 1;
        keyrow3 = 1;
        keyrow4 = 0;

        if (keycolumn1 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '*';
        }
        if (keycolumn2 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '0';
        }
        if (keycolumn3 == 0)
        {
            lcddat('*');
            delay(1000);
            x = 1;
            return '#';
        }
    }
}

// password check function and run the door motor

void check()
{
    //  compare the input value with the assign password value
    if (pin[0] == Epin[0] && pin[1] == Epin[1] && pin[2] == Epin[2] && pin[3] == Epin[3] && pin[4] == Epin[4])
    {
        delay(1000);
        lcdcmd(0x01); // decimal value: 1
        lcdcmd(0x81); // decimal value: 129
        // show pin is correct
        lcddisplay("PIN CORRECT");
        delay(1000);
        // door motor will run
        motorpin1 = 1;
        motorpin2 = 0;
        lcdcmd(0xc1); // decimal value: 193
        // show the door is unlocked
        lcddisplay("DOOR OPENED");
        delay(10000);
        motorpin1 = 1;
        motorpin2 = 0;
        lcdcmd(0x01); // decimal value: 1
    }
    else
    {
        lcdcmd(0x01); // decimal value: 1
        lcdcmd(0x80); // decimal value: 128
        lcddisplay("WRONG PIN");
        delay(1000);
        lcdcmd(0x01); // decimal value: 1
    }
}

// end