Interfacing Seven Segment Display.

[gauravkothari23]

Hi all..
I am trying to interface keypad and Seven Segment display with 89S52.
what i need to do is whatever keys are pressed from keypad, it should show on seven segment display. for Eg. if 2 is pressed from keypad then display should show 2. and so on.
my code is...

#include<reg51.h>
#include<stdio.h>

sbit row0=P2^7; //assigning PORT-0 to read rows
sbit row1=P2^6; //assigning PORT-0 to read rows
sbit row2=P2^5; //assigning PORT-0 to read rows
sbit row3=P2^4; //assigning PORT-0 to read rows
sfr COL=0xA0;   //assigning PORT-2 to read colomns

sbit buz=P3^2;

sbit seg0=P3^0;
sbit seg1=P3^1;
sbit seg2=P3^2;
sbit seg3=P3^3;
sbit seg4=P3^4;
sbit seg5=P3^5;

void msdelay(unsigned int value);
int keypad();

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

unsigned char numbers[6]={"44444"};

void main()
{
unsigned int i;
while(1)
  {
   do
   {
    numbers[i]=keypad();
    i++;
   }
   while(i!=6);
   i=0;
    {
     P1=0x40;
    }
   }

}                       // MAIN ENDS HERE.



void msdelay(unsigned int value)
{
 unsigned int i,j;
 for(i=0;i<value;i++)
 for(j=0;j<100;j++);
}

int keypad()
{
        unsigned char dat[4][4]={'7','8','9','A',        // assigning key matrix
                                 '4','5','6','B',
                                 '1','2','3','-',
                                 '*','0','#','+',};

 unsigned char colloc,rowloc;
 COL=0x0F;
 row0=0;
 row1=0;
 row2=0;
 row3=0;
 while(1)
 {
  do
   {
    do
     {
      msdelay(90);
      colloc=COL;
      colloc&=0x0F;
     }
   while(colloc==0x0F);
   msdelay(90);
   colloc=COL;
   colloc&=0x0F;
   }
  while(colloc==0x0F);
  while(1)
  {
        row0=0;
        row1=1;
        row2=1;
        row3=1;
        msdelay(5);
        colloc=COL;
        colloc&=0x0F;
        if(colloc!=0x0F)
        {
         rowloc=0;
         break;
        }
         row0=1;
         row1=0;
         row2=1;
         row3=1;
         msdelay(5);
         colloc=COL;
         colloc&=0x0F;
         if(colloc!=0x0F)
         {
          rowloc=1;
          break;
         }
         row0=1;
         row1=1;
         row2=0;
         row3=1;
         msdelay(5);
         colloc=COL;
         colloc&=0x0F;
         if(colloc!=0x0F)
          {
           rowloc=2;
           break;
          }
        row0=1;
        row1=1;
        row2=1;
        row3=0;
        msdelay(5);
        colloc=COL;
        colloc&=0x0F;
        if(colloc!=0x0F)
        {
         rowloc=3;
         break;
        }
  }
if(colloc==0x0E)
  return(dat[rowloc][0]);
else if(colloc==0x0D)
  return(dat[rowloc][1]);
else if(colloc==0x0B)
  return(dat[rowloc][2]);
else
  return(dat[rowloc][3]);
}
}

i have not tried anything because i am not getting any idea of how to start with...
because the output from keypad i get is numbers. and to display on seven segment we need hex.
how can i do this.
in my code, in MAIN function i have just tried to save the numbers from what i get from keypad to array numbers[7].
seven segment display are common anode and are connected to port 1 of 89S52.

 

[Easyrider83]

I think it loop forever in while(i!=6);

 

[gauravkothari23]

how looping in the while(i!=6) solve my problem.
what i want is when i press number 2 from keypad the segment should display 2 on it and when again i press 3 it should show 3 and when 4 is press it should show 4 and so on..

 

[betwixt]

What Easyrider83 is pointing out is:

 while(i!=6);
   i=0;
    {
     P1=0x40;
    }

doesn't make a lot of sense.
"while(i!=6);" without something such as an interrupt changing the value of 'i', just sits in a loop forever.
Should the ';' be there and if you meant "if(i != 6)" the following lines should be enclosed in brackets.

Brian.

 

[Easyrider83]

No, I mean that 'i' is undefined at begining. It can be equal to anything.