RTC DS1307 interfacing with 8051 in C using I2C…….

[danesh]

i have used the above code its works..but the clock is running very speed not according to time……….please do help me….

 

 

 

 

Thanks in Advance

[Aniket Patel]

Hi,

thanks to all !

I want to make a multiple alarm regarding to calander using ds1307

can any budy halp me to solve it ?

[nagalaxmi]

 

    hi,

               write_lcd((c/16)+48)

                  write_lcd((c%16)+48);

can any one pls explain me how is works ? am not getting logic behind it ………..

[Arun Sukumaran]

hi nagalaxmi…..,

try this code…. it is easy….

 

 

unsigned char x,y;

//hour

                c=read_i2c(0xd0,0x02);

x= c & 0x0F;

x=x |’0′;

 

                        y= c & 0xF0;

y=y>>4;

y=y | ‘0’;

write_lcd(y);

write_lcd(x);

 

                        write_lcd(‘:’);

[lekh]

hey can anybody tell me which version of Proteus one can download and from where to download some link or so

 

[Anonymous]

RTC interfacing with 8051 using I2C

 

this is my code…….it displays time on lcd but the time doesnt change (my rtc also not changing)…….

 

Can someone please help me…… im stuck at this…..

 

******************main program**********************

 

 

#include<reg51.h>

#include<string.h>

#include “lcd.h”

#include “i2c.h”

 

 

#define SEC   0x00

#define MIN   0x01

#define HOUR  0x02

#define DATE  0x04

#define MONTH 0x05

#define YEAR  0x06

 

 

 

unsigned char read(unsigned char);

void send2lcd(unsigned char );

 

 

void send2lcd(unsigned char value)

{

unsigned char buf = 0;

 

buf = value & 0xF0; /* Filter for high byte */

buf = (buf>>4)|(0x30); /* Convert  to ascii code */

 

lcd_data(buf); /* Show on LCD */

 

buf = value & 0x0F; /* Filter for low byte */

buf = buf | 0x30;       /* Convert to ascii code */

 

lcd_data(buf); /* Show on LCD */

}

 

 

 

unsigned char read(unsigned char addr)

{

unsigned char ret;

start();

write_get(0xD0);

write_get(addr);

start();

write_get(0xD1);

ret = read_get();

stop();

return ret;

 

}

void main()

{

unsigned char sec, min, hour,date,month,year;

 

   while(1) 

{

  lcd_init();

  lcd_cmd(0x80);

  lcd_string(“TIME-“);

 

/* Get Time */

lcd_cmd(0x85);

hour = read(HOUR);

if(hour >= 23)

{

send2lcd(hour);

}

else

{

send2lcd(hour);

}

 

 

lcd_data(‘:’);

 

min = read(MIN);

send2lcd(min);

 

 

lcd_data(‘:’);

 

sec = read(SEC);

if (sec <= 59)

{

send2lcd(sec);

}

else

{

send2lcd(0x00);

}

 

 lcd_cmd(0xC0);

lcd_string(“DATE-“);

 

lcd_cmd(0xC5);

 

 

date = read(DATE);

send2lcd(date);

 

lcd_data(‘/’);

 

month = read(MONTH);

send2lcd(month);

 

lcd_data(‘/’);

 

year = read(YEAR);

send2lcd(year);

 

  }

 

}

 

 

 

**************i2c.h*****************

 

 

sbit SCL = P2^0;

sbit SDA = P2^1;

 

void start(void);

void stop(void);

unsigned char read_get(void);

void write_get(unsigned char);

void ack();

void noack();

void delay(unsigned int);

 

 

void delay(unsigned int s)

{

unsigned int i,j;

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

  for(j=0;j<=10;j++);

}

 

 

void start()

{

  SDA = 1;

SCL = 1;

delay(10);

SDA = 0;

SCL = 0;

}

 

void write_get(unsigned char value)

{

unsigned char i,write;

for(i = 0;i < 8;i++)

  {

write = value&0x80;

SDA = write;

SCL = 1;

delay(10);

SCL = 0;

value = value<<1;

  }

 

SDA = 1;

SCL = 1;

ack();

  delay(10);

SCL = 0;

}

 

 

unsigned char read_get()

{

  unsigned char read = 0x00;

  unsigned char i;

SDA = 1;

 

for(i=0;i<8;i++)

{

SCL = 0;

delay(20);

SCL = 1;

read = read| SDA;

if(i<7)

read = read <<1;

}

noack();

return read;

 

 

}

 

void stop()

{

SDA = 0;

SCL = 1;

delay(10);

SDA = 1; 

SCL =0;

 

}

 

void ack()

{

SDA = 0; /* Clear SDA */

 

delay(10);    

 

SCL = 1;

delay(10);

SCL = 0;

 

SDA = 1; /* Set SDA */

}

 

 

void noack()

{

SDA = 1; /* Set SDA */

 

delay(10);

SCL = 1;

delay(10);

SCL = 0;

 

SCL = 1; /* Set SCL */

}

 

**********************lcd.h**************

 

sfr lcd = 0x90;

 

sbit rs = P3^0;

sbit rw = P3^1;

sbit en = P3^2;

 

void lcd_cmd(unsigned char);

void lcd_init();

void lcd_data(unsigned char);

void delay1(unsigned int);

void lcd_string(unsigned char a[]);

 

void lcd_init()

{

  lcd_cmd(0x01);

lcd_cmd(0x38);

lcd_cmd(0x06);

lcd_cmd(0x0E);

}

 

void lcd_cmd(unsigned char x)

{

  lcd = x;

rs = 0;

rw = 0;

en = 1;

delay1(10);

en = 0;

}

 

void lcd_data(unsigned char z)

{

  lcd = z;

rs = 1;

rw = 0;

en = 1;

delay1(10);

en = 0;

}

 

void delay1(unsigned int y)

{

unsigned int j;

for(;y>0;y–)

for(j=0;j<100;j++);

}

 

void lcd_string(unsigned char a[])

{

unsigned int i;

for(i = 0;i < strlen(a);i++)

{

lcd_data(a);;

}

 

}

 

 

[Sivabalamurugan]

i need what is i2c concept

 

[AJISH ALFRED]

Hi Sivabalamurugan,

Suggest you to go through this tutorial on the following link.

engineersgarage.com/tutorials/twi-i2c-interface

[Anonymous]

THANK U Frnd…………………….

 

[nagar]

/*   '_nop_ ()' ( no operation function) is used for delay purpose 

 

'bit'   is a data tye contain only  1 or 0 (any value other then 0 treated as 1)

 

#include<intrins.h>   is used to avoke from nop() function

 

*/

 

 

 

#include<reg51.h>

#include<stdio.h>

#include<string.h>

#include<intrins.h>

sbit rs=P2^4; 

sbit rw=P2^5; 

sbit en=P2^6; 

 

sbit SCL = P2^0;    // connect to SCL pin (Clock)

sbit SDA = P2^1;    // connect to SDA pin (Data)

 

unsigned char i;

unsigned char Data;

 

#define ACK      0

#define NO_ACK   1

void DelayMs(unsigned int count)

{ 

// mSec Delay 11.0592 Mhz

   unsigned int i;                

   while(count)

    {

       i = 115;

         while(i>0) i–;

       count–;

   }

}

 

void cmd(unsigned char x)

{

P1=x;

rs=0;

rw=0;

en=1;

DelayMs(20);

en=0;

}  

 

void dat(unsigned char x)

{

P1=x;

rs=1;

rw=0;

en=1;

DelayMs(20);

en=0;

}

 

void lcd_init()

{

cmd(0x01);

DelayMs(50);

cmd(0x80);

DelayMs(50);

cmd(0x0e);

DelayMs(50);

cmd(0x38);

}

void string(unsigned char *p)

{

while(*p)

{

dat(*p);

p++;

}

}

void start();

void stop();

void WriteI2C(unsigned char);

unsigned char ReadI2C(bit);   // bit is a data type

 

unsigned int s=0,s1=0,s2=0,h=0,h1=0,h2=0,m=0,m1=0,m2=0;

unsigned char z[50];

void main()

{

lcd_init();

while(1)

{

 

  //   seconds    //

  start();

  WriteI2C(0xD0);   // address of RTC

  WriteI2C(0x00);   // address for seconds

  start();

  WriteI2C(0xD1);   // address of RTC to read value

  s=ReadI2C(ACK);  // after read data send acknowledgement

    stop();

 

//  minutes  //

start();

  WriteI2C(0xD0);   // address of RTC

  WriteI2C(0x01);   // address for minutess

  start();

  WriteI2C(0xD1);   

m=ReadI2C(ACK);

stop();

 

//      hour     //

start();

  WriteI2C(0xD0);   // address of RTC

  WriteI2C(0x02);   // address for hourss

  start();

  WriteI2C(0xD1);   

h=ReadI2C(ACK);

   stop();

 

s1=s&0x0f;

s2=(s&0xf0)>>4;

 m1=m&0x0f;

 m2=(m&0xf0)>>4;

h1=h&0x0f;

h2=(h&0xf0)>>4;

cmd(0x80);

dat(h2+48);

dat(h1+48);

dat(':');

dat(m2+48);

dat(m1+48);

dat(':');

dat(s2+48);

dat(s1+48);

cmd(0xc0);

// sprintf(z,"%d%d:%d%d:%d%d",h2,h1,m2,m1,s2,s1);

// string(z);

}

 

}

//

---

// start I2C

//

---

void Start() // SDA pin is high to low _ when clock is high

{

   SDA = 1;

    SCL = 1;

    _nop_();_nop_();  // for delay

    SDA = 0;

    _nop_();_nop_();  // for delay

    SCL = 0;

    _nop_();_nop_();  // for delay

}

 

//

---

// stop I2C

//

---

void Stop()   // SDA pin is low to high _/ when clock is high

{

    SDA = 0;   

    _nop_();_nop_();  // for delay

    SCL = 1;

    _nop_();_nop_();  // for delay

    SDA = 1;

}

 

//

---

// Write I2C

//

---

void WriteI2C(unsigned char Data)   // data bit is change when clock is change 

{  

 

    for (i=0;i<8;i++)

    {

       SDA = (Data & 0x80) ? 1:0;

       SCL=1;

SCL=0;

         Data<<=1;

}

 

 SCL = 1;    // on this extra clock the ACK is receive by the master

    _nop_();_nop_();

    SCL = 0;

 _nop_();_nop_();  // for delay*

}

 

//

---

// Read I2C  when slave sends the complete data it latches the SDA pin high as no ack for wait of another restart bit

//

---

 

unsigned char ReadI2C(bit ACK_Bit)

{

  

    for (i=0;i<8;i++)

    {

         SCL   = 1;      

         Data<<= 1;

         Data = (Data | SDA);    

         SCL   = 0;

         _nop_();

    }

  

   if (ACK_Bit == 1)

    SDA = 0; // Send ACK     

    else    

    SDA = 1; // Send NO ACK               

  

 SCL = 1;    // on this extra clock the ACK is transmitted by the master

    _nop_();_nop_();

    SCL = 0;

 _nop_();_nop_();  // for delay*

 

    return Data;

}

 

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