LCD based digital clock using 8051 project. Does it work for you?

[Ashton C.]

Hopefully there is a simple explanation for my question.

I assembled the LCD based digital clock using 8051 microcontroller (AT89C51) found here: http://www.engineersgarage.com/microcontroller/8051projects/LCD-based-digital-clock-AT89C51-circuit

But after starting, the seconds are advancing at an accelerated rate approximately 4X the normal rate.  So Minutes advance every 16 seconds. 

What is your experience?

 

This is the project code:

 

<code>

// Program to make a digital clock using LCD

#include<reg51.h>

#define cont_port P3

#define port P1

#define dataport P2  // Data port for LCD

#define m_sec 10

sbit rs = cont_port^0;

sbit rw = cont_port^1;

sbit en = cont_port^6;

sbit dig_hr1=port^0;

sbit dig_min1=port^1;

sbit start=port^2;

sbit am_pm=port^3;

int hr ,hr1=0;

int min,min1=0;

int sec,sec1=0,dig_am_pm=0;



void delay(unsigned int msec)   // Time delay funtion

{

int i,j ;

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

for(j=0;j<1275;j++);

}





void lcd_cmd(unsigned char item)   // Function to send command on LCD

{

dataport = item;

rs= 0;

rw=0;

en=1;

delay(1);

en=0;

return;

}



void lcd_data(unsigned char item)  // Function to send data on LCD

{

dataport = item;

rs= 1;

rw=0;

en=1;

delay(1);

en=0;

return;

}



void lcd_data_string(unsigned char *str)  // Function to send string on LCD

{

int i=0;

while(str!='')

{

lcd_data(str);

i++;

delay(1);

}

return;

}



lcd_data_int(int time_val)   // Function to send number on LCD

{

int int_amt;

int_amt=time_val/10;

lcd_data(int_amt+48);

int_amt=time_val%10;

lcd_data(int_amt+48);

}



void lcd(unsigned char str1[10])  // Function to initialize LCD

{

lcd_cmd(0x38);  //2 LINE, 5X7 MATRIX

lcd_cmd(0x0e);  //DISPLAY ON, CURSOR BLINKING

delay(m_sec);

lcd_data_string(str1);

}



void set_hr1()  // Function to set hour

{

hr1++;

if(hr1>11)

hr1=0;

lcd_cmd(0xc3);

lcd_data_int(hr1);

lcd_data(':');

}



void set_min1()  // Function to set minute

{

min1++;

if(min1>59)

min1=0;

lcd_cmd(0xc6);

lcd_data_int(min1);

}



void main()

{

int k;

start=1;

dig_hr1=1;

dig_min1=1;

lcd_cmd(0x01);

lcd_cmd(0x83);

lcd("SET TIMING");

lcd_cmd(0xc3);

lcd_data_int(hr1);

lcd_data(':');

lcd_data_int(min1);

while(start==0)

{

delay(10);

if(dig_hr1==0)

set_hr1();

if(dig_min1==0)

set_min1();

}



if(am_pm==0)

{

lcd_cmd(0xc8);

  lcd_data_string("am");

  dig_am_pm=0;

}



if(am_pm==1)

{

  lcd_cmd(0xc8);

  lcd_data_string("pm");

  dig_am_pm=1;

}

delay(200);

lcd_cmd(0x01);

while(1)

{

  for(k=0;k<2;k++)

  {

   for(hr=hr1;hr<12;hr++)

   {

    for(min=min1;min<60;min++)

     {

      for(sec=0;sec<60;sec++)

      {

       lcd_cmd(0x82);

       delay(1);

       lcd_data_int(hr);

       lcd_data(':');

       lcd_data_int(min);

       lcd_data(':');

       lcd_data_int(sec);

       if(dig_am_pm==0)

       {

        lcd("am");

       }

       else

       {

        lcd("pm");

       }

       lcd_data_string("    ");

       delay(100);

      }

     }

    min1=0;

    }

  if(dig_am_pm==0)

  dig_am_pm=1;

  else

  dig_am_pm=0;

  hr1=0;

  }

}

}

</code>

[Ashton C.]

Resolved!

 

The Delay(100) at the bottom here:

 

<code>lcd_data_string(”    “);

       delay(100); </code>

 

Had to be changed to 675 to correct the clock speed.  Now the project’s minute is about 60.4 seconds.

 

<code>lcd_data_string(”    “);

       delay(675); </code>

[AJISH ALFRED]

Thanks for sharing how you resolved it, must be defenitely helpful for others!!

[Author]

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