Problem with ds1307 interface with pic16f877a

[rangerskm]

I AM NEW TO INTERFACE OF DS1307 WITH PIC.
can any provide the links for these interface and what is iic protocol ??

 

[thannara123]

Look here
https://saeedsolutions.blogspot.in/2012/12/interfacing-of-pic16f877-with-ds1307.html
learn from there

 

[#MAAM#]

it's very easy if you are using MIKROC compiler.

 

[rangerskm]

Problem in rtc interface with pic16f877a and communicate to pc

COMPILED USING MPLAB IDE HI TECH C COMPILER
i am having little trouble with the rtc interface .i simulated in isis i got the right time in it.when i implemented in hardware.i got some unknown characters in PC when taken the real time values from controller to the PC terminal using UART.

#include<pic.h>       //Define PIC Registers

#include<stdio.h>                  

 

__CONFIG(0x3f72); //Select HS oscillator, Enable (PWRTE,BOREN),

                  //Disable (CPD,CP,WDTEN,In-circuit Debugger





#define LC01CTRLIN    0xd0

#define LC01CTRLOUT 0xd1

#define I2C_FREG   100

#define FOSC       10000

#define BAUD_RATE   9.6       // 9600 Baud rate

#define BAUD_VAL   (char)(FOSC/ (16 * BAUD_RATE )) - 1;         

//Calculation For 9600 Baudrate @10Mhz

 

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

unsigned char data[7]={0x45,0x59,0x71,0x04,0x05,0x10,0x06};

int i;

void DS1307Write(unsigned char,unsigned char);           

void WaitMSSP();                                

unsigned char DS1307Read(unsigned char);

void i2c_init(void);

void ds1307_init(void);

void serial_init(void);

void DelayMs(unsigned int);

void main()

{  




     	
 

   

//************************************************************************
int count=0;

   DelayMs(20);

    ds1307_init();

   serial_init();

   for(i=0;i<7;i++)

   DS1307Write(i,data[i]);                          

   printf("\033[2J");  

   DelayMs(20);

    while(1)

   {

      sec=DS1307Read(0);        // Read second

      min=DS1307Read(1);        // Read minute

      hour=DS1307Read(2);       // Read hour

      day=DS1307Read(3);        // Read day

      date=DS1307Read(4);       // Read date

       month=DS1307Read(5);      // Read month

      year=DS1307Read(6);       // Read year

      printf("Time: %x : %x : %x  ",(hour&0x1f),min,sec);   //Display the Hours, Minutes, Seconds(hours is taken from 5 LSB bits  

      printf("Date: %x / %x / %x    \r",date,month,year);   //Display the Date, Month, Year

      DelayMs(150);

   }

}

        

void DS1307Write(unsigned char addr, unsigned char data)

{

   SEN=1;      //Initiate Start condition on SDA & SCL pins

   WaitMSSP();                             

   SSPBUF=LC01CTRLIN;   // Slave address + Write command

   WaitMSSP();                           

   SSPBUF=addr;         // Write the location

   WaitMSSP();                               

   SSPBUF=data;         // Write the Data

   WaitMSSP();                              

   PEN=1;               // Enable the Stop bit

   WaitMSSP();                               

}

 

unsigned char DS1307Read(unsigned char addr)

{

   unsigned char x;

   RSEN=1;   // Enable the repeated Start Condition

   WaitMSSP ();                          

   SSPBUF=LC01CTRLIN; // Slave address + Write command

   WaitMSSP ();                           

   SSPBUF=addr;     

//Write the location (memory address of Hour, minute, etc...

   WaitMSSP ();                          

   RSEN=1;    // Enable the repeated Start Condition

   WaitMSSP ();                          

   SSPBUF=LC01CTRLOUT; // Slave address + Read command

   WaitMSSP ();                          

   RCEN=1;            // Enable to receive data

   WaitMSSP ();                          

   ACKDT=1;    // Acknowledge the operation (Send NACK)

   ACKEN=1;    // Acknowledge sequence on SDA & SCL pins

   PEN=1;      // Enable the Stop bit

   WaitMSSP ();                          

   x=SSPBUF;   // Store the Receive value in a variable

   return (x);          

}

 

void WaitMSSP()

{

   while(!SSPIF); // SSPIF is zero while TXion is progress

   SSPIF=0;         

}

 

void ds1307_init()

{

   TRISC3=1;      // RC3,RC4 set to I2C Mode(Input)

   TRISC4=1;

   SSPCON=0x28;   // Enable the SDA,SCL & I2C Master Mode

   SSPADD=(FOSC / (4 * I2C_FREG)) - 1;// SSP baud rate 100Khz

   SSPSTAT=0x80;  // Disable slew Rate control

   PORTC=0x18;

   DS1307Write(0,0x00); 

}

 

void serial_init()

{

   TRISC6=1;     // RC7, RC6 set to USART Mode

   TRISC7=1;

   TXSTA=0x24;

// Enable Transmission, Asynchronous mode, High Speed mode

   SPBRG=BAUD_VAL;    // 9600 Baud rate selection

   RCSTA=0x90;   // Enable Serial Port & Continuous Reception

   TXIF=1;       // Enable Transmission

}

 

void putch(unsigned char byte)//Required for printf statement

{

                 

   while(!TXIF); // Wait for the Transmit Buffer to be empty  

   TXREG = byte; // Transmit the Data

}

 

void DelayMs(unsigned int Ms)

{

   int delay_cnst;

   while(Ms>0)

   {

      Ms--;

      for(delay_cnst = 0;delay_cnst <220;delay_cnst++);

   }

}

check the code and say me solution for viewing the correct time in terminal and also please help me to modify the code to display the time in LCD (2*16)DISPLAY

 

[jayanth.devarayanadurga]

Re: Problem in rtc interface with pic16f877a and communicate to pc

Baudrate is not matching or UART data is inverted.

 

[rangerskm]

Re: Problem in rtc interface with pic16f877a and communicate to pc

whats the correct baud rate for this .where it can be edited in the program ??

 

[Raady Here]

Re: Problem in rtc interface with pic16f877a and communicate to pc

why did u mention baudrate as 9.6 ?


"TRISC6=1; // RC7, RC6 set to USART Mode
TRISC7=1; "

You have mentioned both pins as input ( if they are connected to UART ) one should be for RX and One for Tx