Basics
The Real time clock DS1307 IC basically is stand alone time clock. Well, basically we can use a micrcontroller to keep time, but the value would go off as soon as it is powered off.
The RTC DS1307 is a handy solution to keep time all the way, when it is powered by a coin cell.
It is uses I²C (Inter-Integrated Circuit) protocol, referred to as I-squared-C, I-two-C, or IIC for communication with the micrcontroller.
Check the basics of I2C here, if are not familiar with it. For Details of I2C, go through this tutorial.
Schematic
Code
#include <avr\io.h> // io.h contains the defnition of all ports and SFRs #include "lcd.h" //User defined LCD library which conatins the lcd routines #include "ds1307.h" //User defined library which conatins the RTC(ds1307) routines /* start the main program */ void main() { unsigned char sec,min,hour,day,month,year; /* Initilize the lcd before displaying any thing on the lcd */ LCD_Init(); /* Initilize the RTC(ds1307) before reading or writing time/date */ DS1307_Init(); /*Set the time and Date only once */ DS1307_SetTime(0x10,0x40,0x20); // 10:40:20 am DS1307_SetDate(0x04,0x02,0x15); // 4th Feb 2015 /* Display "Time" on first line*/ LCD_DisplayString("Time: "); /* Display "Date" on Second line*/ LCD_GoToLineTwo(); LCD_DisplayString("Date: "); /* Display the Time and Date continuously */ while(1) { /* Read the Time from RTC(ds1307) */ DS1307_GetTime(&hour,&min,&sec); /* Display the time on Firstline-7th position*/ LCD_GoToXY(0,6); LCD_DisplayRtcTime(hour,min,sec); /* Read the Date from RTC(ds1307) */ DS1307_GetDate(&day,&month,&year); /* Display the Date on Secondline-7th position*/ LCD_GoToXY(1,6); LCD_DisplayRtcDate(day,month,year); } }