Problem with clock in DS1337 and 16F877a circuit

[kandy71]

Hi,
I using the DS1337 with the DS32KHZ connected with the 16F877a, however, the clock is loosing 1second every minutes. I cannot understand why.
I did something wrong? I can calibrate the clock?

Thank you

 

[wizpic]

ds1337.h

You have not really given us a lot to go on, it could be a software issue or hardware issue, I had the same problem sometime agobut mine was between1-8 minutes and found it was a software issuse (bug) correct it and it worked ok

what language are you usinf ASM picbaisc ?

wizpic

 

[kandy71]

code pic16f ds1337

Hi,
thank you for your answer
I used CCS with the driver for the ds1307

 

[kandy71]

ds1307 16f877a

Sorry if I post again. But anyone knows how to solve this ?

 

[blueroomelectronics]

DS1337 and 16F877a

Post your code.

 

[kandy71]

Re: DS1337 and 16F877a

This is my code

#include <16F877A.h>
#device *=16
#device ICD=TRUE
#device adc=8

#FUSES NOWDT                    //No Watch Dog Timer
#FUSES HS                       //High speed Osc (> 4mhz)
#FUSES PUT                      //Power Up Timer
#FUSES NOPROTECT                //Code not protected from reading
#FUSES NODEBUG                  //No Debug mode for ICD
#FUSES NOBROWNOUT               //No brownout reset
#FUSES NOLVP                    //No low voltage prgming, B3(PIC16) or B5(PIC18) used for I/O
#FUSES NOCPD                    //No EE protection
#FUSES WRT_50%                  //Lower half of Program Memory is Write Protected

#use delay(clock=18432000)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)
#ifndef DS1337_SDA
#define DS1337_SDA  PIN_C4
#define DS1337_SCL  PIN_C3
#endif

#use i2c(master, sda=DS1337_SDA, scl=DS1337_SCL)
#include <LCD.C>
#include "ds1337.h"



// Main Program
void main(void)
{
   date_time_t dt;
   ds1337_init();
   dt.month   = 12;    // December
   dt.day     = 31;    // 31
   dt.year    = 06;    // 2006
   dt.hours   = 23;    // 23 hours (11pm in 24-hour time)
   dt.minutes = 59;    // 59 minutes 
   dt.seconds = 50;    // 50 seconds
   ds1337_set_datetime(&dt);
      
   DS1337_read_datetime(&dt);
   
   lcd_init();
   printf("Start\n\r"); 
   
   
   while(true)
   {
      delay_ms(300);
      ds1337_read_datetime(&dt);
      printf(lcd_putc,"\f\%02d/\%02d/\%02d\n",dt.day,dt.month,dt.year);
      printf(lcd_putc,"\%02d:\%02d:\%02d", dt.hours,dt.minutes,dt.seconds); 
   }
}

And this is the ds1337.h

https://www.ccsinfo.com/forum/viewtopic.php?p=69975

 

[kandy71]

Re: DS1337 and 16F877a

Any idea?

 

[radioelf]

Re: DS1337 and 16F877a

Any idea?

dt.month = 12; // December
dt.date = 31, //DAY MONTH
dt.day = 1; // DAY OF THE WEEK
dt.year = 14; // 2006
dt.hours = 23; // 23 hours (11pm in 24-hour time)
dt.minutes = 59; // 59 minutes
dt.seconds = 50; // 50 seconds