Help me fix problem in I2C-RTC code

Hi ,I face a Problem in inter facing RTC, I wrote the code in C using the Hitech C compiler,I found that the My code works properly in simulation and doesnt work when freely run continously or programming mode,I use MPLAB IDE and ICD2 Debugger

The code I wrote is posted below, I wanted an Immediate help, So please find me some solution where the problem could be.. or check where i have made the mistake..

I simply displayed the data i get initially but the seconds is not updating.. and getting struck up... if that does then i can manage displaying the formated RTC data.. check my code and tell me a solution..

#include<htc.h>

#define I2C_START SEN=1
#define I2C_STOP PEN=1
#define REP_START RSEN=1

//RTC DATA INDEX
#define SEC 00
#define MIN 01
#define HRS 02
#define DAY 03
#define DATE 04
#define MONTH 05
#define YEAR 06
#define START_UP_SCREEN 01

//LCD
#define RS RE0 //Register select bit is connected PORTE.0 so PORTE.0 is defined as RS
#define LRW RE2 //Read or Write bit is connected PORTE.1 so PORTE.0 is defined as RW
#define EN RE1 //Enable bit is connected PORTE.2 so PORTE.0 is defined as RS
#define LCD PORTD //LCd Data pins are connected to the PORTD

void I2C_ISR();
void RTC_WRITE();
void RTC_READ();
void LCD_INIT(void);
void LCD_CMD(unsigned char cmd);
void DISP_DATA(const char *dat);
void DISP_CHAR(char dat);
void Delay(unsigned int );
void DISP_UPDATE();

bit ACCESS_RTC,SEND_ADDR_FLAG,RW_FLAG,REPTD_START,SEND_STOP,CHECK_ACK=0;
bit DATA_RCVD=0,DISP_TIME;

unsigned char DATE_TIME[7];
unsigned char RW_DAT;
unsigned char count;
unsigned int DELAY_COUNT;
unsigned char PROCESS_STAT;

const char company_name[]="Emtronics Systems";

void main()
{
unsigned int j;
//Port line initializations
PORTA=0x00;
TRISA=0x00;
ADCON1=0x06;
TRISE=0x00;
TRISD=0x00;
TRISC=0x7F;
RC7=0;
PORTA=0x08;
//while(1)
for(j=0;j<=10000;j++)
{
PORTA=0x08;
Delay(4);
PORTA=0x00;
Delay(1);
}
//DATE TIME INITIALIZATIONS
DATE_TIME[SEC]=0x00;
DATE_TIME[MIN]=0x55;
DATE_TIME[HRS]=0x67;
DATE_TIME[DAY]=0x02;
DATE_TIME[DATE]=0x12;
DATE_TIME[MONTH]=0x12;
DATE_TIME[YEAR]=0x11;
//DATE_TIME[7]=0x00;
DISP_TIME=1;

ACKSTAT = 1;
ACCESS_RTC=1;

LCD_INIT();
DISP_DATA(&company_name);
RTC_WRITE();
//OPTION= 0x07;
//INTCON=0x20;
PROCESS_STAT=0x01;

while(1)
{
I2C_ISR();
LCD_CMD(0xC1);
if(ACCESS_RTC)
DISP_UPDATE();
RTC_READ();

}
}

void DISP_UPDATE()
{
unsigned int i=0;
LCD_CMD(0xC0);
if(DISP_TIME)
{
if(PROCESS_STAT==START_UP_SCREEN)
{
do
{
DISP_CHAR(0x30+(0x0F&(DATE_TIME>>4)));
DISP_CHAR(0x30+(0x0F&DATE_TIME));
DISP_CHAR(':');
i++;
}while(i<=3);
}
}
}
/**********************************************************************************************************************************************
* LCD_INIT()
***********************************************************************************************************************************************
*Function arguments : Nil
*Functions Returns : Nil
*Function Description :This function will initialize the LCD by giving the basic Initialization commands to the LCD.
* It also specifies the 4 bit or 8bit operation through the commands given.
*
***********************************************************************************************************************************************/
void LCD_INIT()
{
LCD_CMD(0x38);
LCD_CMD(0x0E);
LCD_CMD(0x01);
LCD_CMD(0x06);
LCD_CMD(0x80);
}
/**********************************************************************************************************************************************
* LCD_CMD()
***********************************************************************************************************************************************
*Function arguments : the Command to be passed to the LCD is passed as an argument.
*Argument Type : unsigned character
*Functions Returns : Nil
*Return Type : Nil
*Function Description :This function will get an unsigned character as an argument and will transmit the argument to the LCD as a command
*
***********************************************************************************************************************************************/
void LCD_CMD(unsigned char cmd)
{
LRW=0;
LCD=cmd;
RS=0;
EN=1;
Delay(10);
EN=0;
}

/**********************************************************************************************************************************************
* DISP_DATA()
***********************************************************************************************************************************************
*Function arguments : starting address of the array of the data to be displayed
*Functions Returns :Nil
*Function Description :This Function will take the starting address of any array of string to be displayed on the LCD.
* Then it will transmit the array of data that are to be displayed one by one.
*
***********************************************************************************************************************************************/
void DISP_DATA(const char *dat)
{
do
{
DISP_CHAR(*dat++);
}while(*dat);
}

/**********************************************************************************************************************************************
* DISP_CHAR()
***********************************************************************************************************************************************
*Function arguments : Character data to be displayed.
*Functions Returns :Nil
*Function Description :This function will display the character data that is passed as an argument to this function
*
***********************************************************************************************************************************************/
void DISP_CHAR(char dat)
{
LRW=0;
LCD=dat;
RS=1;
EN=1;
Delay(10);
EN=0;
}

void Delay(unsigned int n)
{
unsigned int i,j;

for(i=0;i<=n;i++)
for(j=0;j<=10;j++);
}

/***************************************************************************************************
RTC_WRITE()



*****************************************************************************************************/
void RTC_WRITE()
{
if(ACCESS_RTC)
{ //IF ACCESS_RTC is not set, RTC already under use.
SSPSTAT=0b10000000;
SSPCON=0b00011000;
SSPADD=0x1F;
RW_DAT=0xFE;
RW_FLAG=0;
REPTD_START=0;
SSPIF=0;
ACKSTAT=0;
SSPIE=0;
SSPEN=1;
//SEN=1;
I2C_START;
//while(!SSPIF);
//while(RW);
//CHECK_ACK=1;
//ACKSTAT=0;
//SEND_ADDR_FLAG=1;
//SSPIF=0;
//SSPIE=1;
//SSPBUF=0b11010000;
//if(WCOL)
// {
// LCD_CMD(0xC0);
// DISP_DATA("I2C BUS ERROR");
// }
//while(!SSPIF);
//while(ACKSTAT);
//LCD_CMD(0xC0);
//DISP_CHAR('A');
ACCESS_RTC=0;
}
}








/***************************************************************************************************
RTC_READ()



*****************************************************************************************************/


void RTC_READ()
{
if(ACCESS_RTC)
{
SSPSTAT=0b10000000;
SSPCON=0b00011000;
SSPADD=0x1F;
RW_DAT=0xFE;
RW_FLAG=1;
SEND_ADDR_FLAG=1;
REPTD_START=0;
SSPIF=0;
ACKSTAT=0;
SSPIE=0;
SSPEN=1;
I2C_START;
ACCESS_RTC=0;
}
}

/***************************************************************************************************
I2C_ISR()



*****************************************************************************************************/

void I2C_ISR()
{
if(SSPIF)//&&SSPEN&&(SSPCON&0x0F==0x08))
{
//I2C INTERRUPT SERVICE ROUTINE
SSPIF=0;
if((START && !CHECK_ACK) || ACKSTAT)
{

CHECK_ACK=1;
ACKSTAT=0;
while(RW);
SSPBUF=0b11010001&RW_DAT;
// LCD_CMD(0xC0);
// DISP_CHAR('y');
if(!RW_FLAG)
{
SEND_ADDR_FLAG=1;
}
}
else if(!BF && DATA_RCVD)
{
DATE_TIME[count]=SSPBUF;
count++;
if(count==0x07)
{
count=0;
ACKDT=1;
ACKEN=1;
SEND_STOP=1;
DISP_TIME=1;
}
else
{
ACKDT=0;
ACKEN=1;
}
DATA_RCVD=0;
//BF=0;
}
else if(SEND_STOP)
{
PEN=1;
SEND_STOP=0;
}
else if(STOP)
{
// while(RW);
//SSPADD=0x00;
ACCESS_RTC=1;
SSPIE=0;
CHECK_ACK=0;
// SSPBUF=0x00;
SSPCON=0x00;
// DISP_CHAR('S');
}
else if((!ACKSTAT) && (CHECK_ACK))
{
while(RW);
if(SEND_ADDR_FLAG)
{
SSPBUF=0x00;//to be continued
count=0x00;
SEND_ADDR_FLAG=0;
//LCD_CMD(0xC0);
}
else if(!REPTD_START)
{
if(RW_FLAG==1)
{
RSEN=1;
RW_DAT=0xFF;
count=0;
REPTD_START=1;
CHECK_ACK=0;
}
else
{
if(count<0x07)
{
SSPBUF=DATE_TIME[count];
count++;
LCD_CMD(0xC0);
DISP_CHAR(count+0x30);
}
else
{
PEN=1;
CHECK_ACK=0;
}

}
}
else if(REPTD_START)
{
SSPCON2=0x08;
DATA_RCVD=1;
}
// ACKSTAT=1;
}
if(WCOL)
{
LCD_CMD(0xC0);
DISP_DATA("I2C BUS ERROR");
}
}
}

Thanking you,
Kannan

Re: I2C-RTC code problem

Which RCT chip you are using and what micro controller you are using?

Re: I2C-RTC code problem

DS1307 and PIC16F877A
Its working in when emulated using ICD 2 debugger but doesnt work on free running mode.. have you ever faced this problem...

Re: I2C-RTC code problem

Do you have pull-up resistors on the interface lines?

Anand Dhuru

Re: I2C-RTC code problem

Yes I have 10K pull ups as specified in data sheet .. i have used the circuit diagram recommended in Dallas semiconductor DS1307 datasheet

I am not able to under stand why my code doesn't work on free running mode and why it works only in debuggng mode.... since it works on hardware debugging and doesnt work on real time i am not able solve by debugging...
so help me... if you have faced such problems...

thank you,

Re: I2C-RTC code problem

Does the debugging mode runs in the same speed as free running mode?

If the debugging mode is running slower than free running, then it is timing problem, then you should insert delays.

Yes I have 10K pull ups as specified in data sheet

Click to expand...

Where in the datasheet it is mentioned?

I normally use 4,7k resistors as pullup.