need help,,,, regarding caparking using 8051

[shahzadiqbal]

hi all
i faced problem in car parking code in c..
i have 5 empty slot.... 1 by 1 counter is decreasing.. but problem is that when counter is reached to 0... it cant stop

#include<reg51.h>
#define lcdport P2
sbit senin=P1^0;
sbit senout=P1^1;
sbit door1_a=P3^4;
sbit door1_b=P3^5;
sbit door2_a=P3^6;
sbit door2_b=P3^7;
sbit rs=P3^0;
sbit rw=P3^1;
sbit en=P3^2;
sbit led=P1^7;
sbit pulse=P3^5;
int k,p;
unsigned int count=5;
unsigned int digit[2];
void entry_door_open();
void exit_door_open();
void entry_door_close();
void exit_door_close();
void exit_door_stop();
void entry_door_stop();
void lcdcmd(char);
void lcdint();
void lcddata(char);
void lcdstring(char *);
void delay(unsigned int);
void convert(unsigned int);
void ldelay(unsigned int);
          
void main()
{
        lcdint();
        led=0;
        senin=0;
        senout=0;
          lcdstring("DESIGNED BY");
        lcdcmd(0xc0);
          lcdstring("SHAHZAD IQBAL");
        lcdcmd(0xc0);
          delay(60000);
          lcdcmd(0x01);
        lcdstring("AUTOMATIC CAR");
        lcdcmd(0xc0);
        lcdstring("PARKING SYSTEM");
        delay(50000);
        lcdcmd(0x01);
        lcdstring("parking left:");
        lcdcmd(0x8d);
        convert(count);
        while(1)
        {
      
        lcdcmd(0x8d);
        led=1;
        ldelay(10);
        if(senin==1)
        {
        count=count-1;
        convert(count);
        entry_door_open();
        while(senin==1);
        delay(30000);
      
        entry_door_close();
        entry_door_stop();
        delay(5000);
       }
       else if(senout==1)
       {
        count=count+1;
        convert(count);
        exit_door_open();
        while(senout==1);
        delay(60000);
        delay(60000);
        exit_door_close();
        exit_door_stop();
        delay(5000);
        }
          }
            }
void convert(unsigned int value)
{
 led=0;    
  for(k=0;k<2;k++)
  {
        digit[k]=value%10;
        value=value/10;
        }
        for(p=1;p>=0;p--)
        {
       lcddata(digit[p]+48);
        ldelay(1);
        }
        if (count==0)
        {
        lcdcmd(0x8d);
        lcdstring("full");
        }
    
        ldelay(10);
        }
 void delay(unsigned int x)
 {
        unsigned int i;
        for(i=0;i<x;i++);
}
 void lcdint()
{
         lcdcmd(0x38);
         delay(500);
         lcdcmd(0x01);
         delay(500);
         lcdcmd(0x0c);
         delay(500);
         lcdcmd(0x80);
         delay(500);
         lcdcmd(0x0e);
         delay(500);
    }

void lcdcmd(char value)
       {
         lcdport = value;
         rw=0;
         rs=0;
         en=1;
         delay(500);
         en=0;
       }  
void lcdstring(char *p)
      {
         while(*p!='\0')
          {
            lcddata(*p);
            delay(2000);
            p++;
          }
      }
 void lcddata(char value)
{
         lcdport=value;
         rs=1;
         rw=0;
         en=1;
         delay(500);
         en=0;
}
void ldelay(unsigned int x)
          {
               unsigned int i,j;
           for (i=0;i<=x;i++)
           for (j=0;j<=1275;j++);
       }
void entry_door_open()
{
lcdcmd(0xc0);
lcdstring("               ");
lcdcmd(0xc0);
lcdstring("opening door");
door1_a=1;
door1_b=0;
delay(60000);
delay(60000);
}
void entry_door_close()
{
lcdcmd(0xc0);
lcdstring("               ");
lcdcmd(0xc0);
lcdstring("clossing door");
door1_a=0;
door1_b=1;
delay(60000);
delay(60000);
}
void entry_door_stop()
{
lcdcmd(0xc0);
lcdstring("               ");
lcdcmd(0xc0);
lcdstring("door closed");
door1_a=0;
door1_b=0;
delay(60000);
delay(60000);
lcdcmd(0xc0);
lcdstring("               ");
}
void exit_door_open()
{
lcdcmd(0xc0);
lcdstring("               ");
lcdcmd(0xc0);
lcdstring("opening door");
door2_a=0;
door2_b=1;
delay(60000);
delay(60000);
}
void exit_door_close()
{
lcdcmd(0xc0);
lcdstring("               ");
lcdcmd(0xc0);
lcdstring("clossing door");
door2_a=1;
door2_b=0;
delay(60000);
delay(60000);
}
void exit_door_stop()
{
lcdcmd(0xc0);
lcdstring("               ");
lcdcmd(0xc0);
lcdstring("door closed");
door2_a=0;
door2_b=0;
delay(60000);
delay(60000);
lcdcmd(0xc0);
lcdstring("               ");
}

 

[Ian Rogers]

Change this:-
count=count-1;

to this:-
if (count > 0 ) count-1;

Next time try and use code tags...