Plz again helpe to understand programe for digital clock using seven segment

[Amit Kumar]

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)

May anyone tell me what is dig_disp & why it is incremented. What is the meaning of line

dig_disp=dig_disp%4;

 

[dagakshay]

send the link where you reffering this code…

[romel emperado]

that is only a variable…

 

it needs to increment so that it will match to the switch case..

[Amit Kumar]

 

 

Dear sir,

 

I have pasted  the  programe.

 

And tell me what is the variable for dig_disp. Please make me understand it.

 

#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();

}

}

}

}

}

}

 

[Amit Kumar]

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;

dig_disp is meant for what. It is variable, i understand it. But this variable is for what? & why it is written dig_disp=dig_disp%4;

[romel emperado]

dig_disp++;  // variable is increamented



dig_disp=dig_disp%4;  // as u can see this line using modulo any value

switch(dig_disp)

dig_disp=dig_disp%4;  // as u can see this line is using modulo any value of  this variable will be check by the switch case..



this is simply getting the timing if you want faster timing you can change that in 2 instead of 4..



try to experiment so that will know what happens if you change that line..

 

[Amit Kumar]

Now, i understand the programe.

[Author]

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