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++)
;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);;
}
}