Real Time Clock(DS1307) with AVR
    Revision as of 12:39, 4 February 2015 by Amruta (Talk | contribs)

    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.

    Schematic

    [1]

    Schematic AVR Interfacing RTC.JPG

    Code

    1. #include <avr\io.h>    // io.h contains the defnition of all ports and SFRs
    2. #include "lcd.h"	         //User defined LCD library which conatins the lcd routines
    3. #include "ds1307.h"    //User defined library which conatins the RTC(ds1307) routines
    4.  
    5. /* start the main program */
    6. void main() 
    7. {
    8.    unsigned char sec,min,hour,day,month,year;
    9.  
    10.   /* Initilize the lcd before displaying any thing on the lcd */
    11.     LCD_Init();
    12.  
    13.   /* Initilize the RTC(ds1307) before reading or writing time/date */
    14.     DS1307_Init();
    15.  
    16.   /*Set the time and Date only once */
    17.    DS1307_SetTime(0x10,0x40,0x20);  //  10:40:20 am
    18.    DS1307_SetDate(0x04,0x02,0x15);  //  4th Feb 2015
    19.  
    20.   /* Display "Time" on first line*/
    21.    LCD_DisplayString("Time: ");
    22.  
    23.    /* Display "Date" on Second line*/
    24.    LCD_GoToLineTwo();
    25.    LCD_DisplayString("Date: ");
    26.  
    27.    /* Display the Time and Date continuously */ 
    28.    while(1)
    29.     {
    30. 	 /* Read the Time from RTC(ds1307) */ 
    31.         DS1307_GetTime(&hour,&min,&sec);        
    32.  
    33. 	/* Display the time on Firstline-7th position*/
    34.         LCD_GoToXY(0,6); 		 
    35.         LCD_DisplayRtcTime(hour,min,sec);
    36.  
    37.  
    38. 	 /* Read the Date from RTC(ds1307) */ 
    39.          DS1307_GetDate(&day,&month,&year);        
    40.  
    41. 	 /* Display the Date on Secondline-7th position*/
    42.          LCD_GoToXY(1,6); 		 
    43.          LCD_DisplayRtcDate(day,month,year);
    44.     }		
    45.  
    46.   }
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