Hai friends,

I used this code for doing a project from engineersgarage.com,which is a digital clock using 8051.But the

lcd 7 segments are not working properly.



/ Program to demonstrate the principle of digital clock. this digital clock displays two minute digits and two second digits



#include<reg51.h>

sbit dig_ctrl_4=P1^0;        //Declaring control pins of the seven segments

sbit dig_ctrl_3=P1^1;

sbit dig_ctrl_2=P1^2;

sbit dig_ctrl_1=P1^3;

unsigned char dig_disp=0;

int min2;

int min1;

int sec2;

int sec1;

char digi_val[10]={0x40,0xF9,0x24,0x30,0x19,0x12,0x02,0xF8,0x00,0x10};



void delay()        //Function to provide a time delay of approx. 1 second. using Timer 1.

{

int i;

for(i=0;i<20;i++)

{

TL1=0xFD;

TH1=0x4B;

TR1=1;

while(TF1==0);

TR1=0;

TF1=0;

}

}



void display() interrupt 1        //Function to display the number using seven segmnet multiplexing. For more details refer seven segment multiplexing.

{

TL0=0x36;        //Reloading Timer0

TH0=0xf6;

P2=0xFF;

dig_ctrl_1 = dig_ctrl_3 = dig_ctrl_2 = dig_ctrl_4 = 0;

dig_disp++;

dig_disp=dig_disp%4;

switch(dig_disp)

{

case 0:

P2=digi_val[sec1];

dig_ctrl_1 = 1;

break;



case 1:

P2=    digi_val[sec2];

dig_ctrl_2 = 1;

break;



case 2:

P2=    digi_val[min1];

dig_ctrl_3 = 1;

break;



case 3:

P2=    digi_val[min2];

dig_ctrl_4 = 1;

break;

}

}



void main()

{

TMOD=0x11;        //Intialize Timer 0

TL0=0x36;

TH0=0xF6;

IE=0x82;        // Enable Timer 0 interrupt

TR0=1;        //Start Timer 0

while(1)        //Start clock

{

min2=min1=sec2=sec1=0;

for(min2=0;min2<6;min2++)

{

for(min1=0;min1<10;min1++)

{

for(sec2=0;sec2<6;sec2++)

{

for(sec1=0;sec1<10;sec1++)

{

delay();

}

}

}

}

}

}