Digital clock " DS1307 RTC" with PIC16F877A microcontroller and I2C

            Digital clock " DS1307 RTC" with PIC16F877A microcontroller and I2C:

#include <xc.h>                          // Include XC8 compiler header file

#include "config.h"                      // Include configuration header file specific to the project

#define _XTAL_FREQ 4000000               // Define the crystal frequency for delay calculation

#define RS PORTBbits.RB0                // Define LCD RS pin

#define RW PORTBbits.RB1                // Define LCD RW pin

#define EN PORTBbits.RB2                // Define LCD EN pin

#define delay for(i=0;i<1000;i++)       // Define delay macro

#define ds_adress 0xD0                  // Define DS1307 I2C address

#define second 0x00                     // Define DS1307 register addresses

#define minute 0x01

#define hour   0x02

#define day    0x03

#define date   0x04

#define month  0x05

#define year   0x06

#define control_reg 0x07

void ds_write(char _second, char _minute, char _hour, char _day, char _date, char _month, char _year);

void ds_read(char slave_adress, char register_adress);

void bcd_to_ascii(unsigned char value);

char decimal_to_bcd(unsigned char value);

void lcd_data(unsigned char data);

void lcd_comand(unsigned char cmd);

void lcd_string(const unsigned char *str, unsigned char num);

void lcd_init();

unsigned char __sec, __min, __hr, __day, __date, __month, __yr, __con;  // Declare variables to store time and control data

void main(void) {

    TRISC = 0xFF;                         // Configure PORTC as input

    SSPADD = 9;                           // Set I2C clock frequency

    SSPCON = 0x28;                        // Configure I2C master mode

    TRISD = 0X00;                         // Configure PORTD as output

    PORTD = 0X00;                         // Initialize PORTD

    TRISB = 0X00;                         // Configure PORTB as output

    PORTB = 0X00;                         // Initialize PORTB

    lcd_init();                           // Initialize LCD

    lcd_comand(0x80);                     // Set cursor position for clock display

    lcd_string("clock:", 6);              // Display "clock:" on LCD

    lcd_comand(0xC0);                     // Set cursor position for date display

    lcd_string("DATE:", 5);               // Display "DATE:" on LCD

    ds_write(3, 2, 1, 1, 5, 4, 20);       // Write initial time and date to DS1307

    __delay_ms(300);                      // Delay for stability

    while (1) {

        __delay_ms(20);                   // Delay for stability

        ds_read(ds_adress, 0);            // Read time and date from DS1307

    }

}

char decimal_to_bcd(unsigned char value) {

    unsigned char msb, lsb, hex;         // Declare variables for storing BCD value

    msb = value / 10;                    // Get the most significant digit

    lsb = value % 10;                    // Get the least significant digit

    hex = ((msb << 4) + lsb);            // Convert to BCD format

    return hex;                          // Return BCD value

}

void bcd_to_ascii(unsigned char value) {

    unsigned char bcd;                   // Declare variable for storing BCD value

    bcd = value;

    bcd = bcd & 0xf0;                    // Extract most significant digit

    bcd = bcd >> 4;                      // Shift to right

    bcd = bcd | 0x30;                    // Convert to ASCII

    lcd_data(bcd);                       // Display most significant digit

    bcd = value;

    bcd = bcd & 0x0f;                    // Extract least significant digit

    bcd = bcd | 0x30;                    // Convert to ASCII

    lcd_data(bcd);                       // Display least significant digit

}

void lcd_data(unsigned char data) {

    PORTD = data;                        // Write data to PORTD

    RS = 1;                              // Set RS pin high for data

    RW = 0;                              // Set RW pin low for write

    EN = 1;                              // Set EN pin high to enable

    delay;                               // Delay for stability

    EN = 0;                              // Set EN pin low to disable

}

void lcd_comand(unsigned char cmd) {

    PORTD = cmd;                         // Write command to PORTD

    RS = 0;                              // Set RS pin low for command

    RW = 0;                              // Set RW pin low for write

    EN = 1;                              // Set EN pin high to enable

    delay;                               // Delay for stability

    EN = 0;                              // Set EN pin low to disable

}

void lcd_string(const unsigned char *str, unsigned char num) {

    unsigned char i;                    // Declare loop variable

    for (i = 0; i < num; i++) {         // Loop through each character in the string

        lcd_data(str[i]);               // Display each character on LCD

    }

}

void lcd_init() {

    lcd_comand(0x38);                   // Initialize LCD in 2 lines, 5x7 matrix

    lcd_comand(0x0C);                   // Display on, cursor off

    lcd_comand(0x06);                   // Entry mode: auto-increment cursor

}

void ds_write(char _second, char _minute, char _hour, char _day, char _date, char _month, char _year) {

    SSPCON2bits.SEN = 1;                // Start condition

    while (SSPCON2bits.SEN);            // Wait for start condition to complete

    PIR1bits.SSPIF = 0;                 // Clear SSP interrupt flag

    SSPBUF = ds_adress;                 // Send DS1307 address with write bit

    while (!PIR1bits.SSPIF);            // Wait for transmission to complete

    PIR1bits.SSPIF = 0;                 // Clear SSP interrupt flag

    if (SSPCON2bits.ACKSTAT) {          // Check for ACK

        SSPCON2bits.PEN = 1;            // End condition

        while (SSPCON2bits.PEN);        // Wait for end condition

        return;                         // Return if ACK not received

    }

    SSPBUF = second;                    // Send address of second register

    while (!PIR1bits.SSPIF);            // Wait for transmission to complete

    PIR1bits.SSPIF = 0;                 // Clear SSP interrupt flag

    if (SSPCON2bits.ACKSTAT) {          // Check for ACK

        SSPCON2bits.PEN = 1;            // End condition

        while (SSPCON2bits.PEN);        // Wait for end condition

        return;                         // Return if ACK not received

    }

    // Write time and date values to DS1307 registers similar to the above approach

    SSPBUF = 0x00;                      // Dummy write to end transmission

    while (!PIR1bits.SSPIF);            // Wait for transmission to complete

    PIR1bits.SSPIF = 0;                 // Clear SSP interrupt flag

    SSPCON2bits.PEN = 1;                // End condition

    while (SSPCON2bits.PEN);            // Wait for end condition

}

void ds_read(char slave_adress, char register_adress) {

    // Start condition

    SSPCON2bits.SEN = 1;

    while (SSPCON2bits.SEN); // Wait for start condition to complete

    PIR1bits.SSPIF = 0;      // Clear SSP interrupt flag

    // Send slave address with write bit

    SSPBUF = slave_adress;

    while (!PIR1bits.SSPIF); // Wait for transmission to complete

    PIR1bits.SSPIF = 0;      // Clear SSP interrupt flag

    // Check for ACK

    if (SSPCON2bits.ACKSTAT) {

        SSPCON2bits.PEN = 1;  // End condition

        while (SSPCON2bits.PEN); // Wait for end condition

        return; // Return if ACK not received

    }

    // Send repeated start condition

    SSPCON2bits.RSEN = 1;

    while (SSPCON2bits.RSEN); // Wait for repeated start condition to complete

    PIR1bits.SSPIF = 0;       // Clear SSP interrupt flag

    // Send register address

    SSPBUF = register_adress;

    while (!PIR1bits.SSPIF); // Wait for transmission to complete

    PIR1bits.SSPIF = 0;      // Clear SSP interrupt flag

    // Check for ACK

    if (SSPCON2bits.ACKSTAT) {

        SSPCON2bits.PEN = 1;  // End condition

        while (SSPCON2bits.PEN); // Wait for end condition

        return; // Return if ACK not received

    }

    // Send repeated start condition

    SSPCON2bits.RSEN = 1;

    while (SSPCON2bits.RSEN); // Wait for repeated start condition to complete

    PIR1bits.SSPIF = 0;       // Clear SSP interrupt flag

    // Send slave address with read bit

    SSPBUF = (slave_adress + 1);

    while (!PIR1bits.SSPIF); // Wait for transmission to complete

    PIR1bits.SSPIF = 0;      // Clear SSP interrupt flag

    // Check for ACK

    if (SSPCON2bits.ACKSTAT) {

        SSPCON2bits.PEN = 1;  // End condition

        while (SSPCON2bits.PEN); // Wait for end condition

        return; // Return if ACK not received

    }

    // Enable receive mode

    SSPCON2bits.RCEN = 1;

    while (!SSPSTATbits.BF); // Wait for data to be received

    __sec = SSPBUF;          // Store seconds value

    // Send ACK

    SSPCON2bits.ACKDT = 0;

    SSPCON2bits.ACKEN = 1;

    while (SSPCON2bits.ACKEN); // Wait for ACK to be sent

    // Receive minute value

    SSPCON2bits.RCEN = 1;

    while (!SSPSTATbits.BF); // Wait for data to be received

    __min = SSPBUF;          // Store minutes value

    // Send ACK

    SSPCON2bits.ACKDT = 0;

    SSPCON2bits.ACKEN = 1;

    while (SSPCON2bits.ACKEN); // Wait for ACK to be sent

    // Similar process for hour, day, date, month, year, and control registers

    // Send NACK

    SSPCON2bits.ACKDT = 1;

    SSPCON2bits.ACKEN = 1;

    while (SSPCON2bits.ACKEN); // Wait for NACK to be sent

    // End condition

    SSPCON2bits.PEN = 1;

    while (SSPCON2bits.PEN); // Wait for end condition to complete

    // Display time on LCD

    lcd_comand(0x88);          // Set LCD cursor position

    bcd_to_ascii(__hr);        // Display hour

    lcd_data(":");             // Display colon

    bcd_to_ascii(__min);       // Display minute

    lcd_data(":");             // Display colon

    bcd_to_ascii(__sec);       // Display second

    // Display date on LCD

    lcd_comand(0xC7);          // Set LCD cursor position

    bcd_to_ascii(__date);      // Display date

    lcd_data("/");             // Display slash

    bcd_to_ascii(__month);     // Display month

    lcd_data("/");             // Display slash

    bcd_to_ascii(__yr);        // Display year

}