checking sequence using IF statement

[ycho]

Hi

I am trying to check the sequence using if statement.
first : IR1 and IR3 goes low and IR2 and IR4 stay high
check by while loop, if it is true then go to next if statement.
second : IR1 ,IR2,IR3 and IR4 all goes low.
check by while loop, if it is true then go to next if statement.
lastly :IR1 and IR3 goes high and IR2 and IR4 stay low.

if fulfill above requirement, LCD will increment by one.
I had wrote the program but the program doesn't work.
can someone figure out the problem for me.
below is my code

#include <16f877a.h>
#use delay(clock=20000000)
#fuses hs,noprotect,nowdt,nolvp
#define use_portb_lcd TRUE 
#include <lcd.c>

#define IR1 Pin_A0
#define IR2 Pin_A1
#define IR3 Pin_A3
#define IR4 Pin_A4


void main()
{  
   int people_in = 0, people_out = 0;
   
   set_tris_a(0b00001111);
   lcd_init();

   lcd_putc("\fAutomatic Room");
   lcd_putc("\nLight Controller");
   delay_ms(5000);
   lcd_putc("\f");


display_1st :
   
   lcd_gotoxy(1,1);
   lcd_putc("People in  =  \n");
   lcd_putc("People out =  \n");
   
   lcd_gotoxy(14,1);
   printf(lcd_putc,"%3u",people_in);
       
 do{
   
if (input(IR1)==0 && input(IR3) ==0 && input(IR2)==1 && input(IR4)==1)  
{
while((input(IR1) && input(IR3)) ^ (input(IR2) && input(IR4)));         // (0 AND 0) = 0  (1 AND 1) = 1      0 XOR 1 = 1= TRUE
if (input(IR1)==0 && input(IR3) ==0 && input(IR2)==0 && input(IR4)==0)
{
while((!input(IR1) && !input(IR3)) && (!input(IR2) && !input(IR4)));    // 1 AND 1 AND 1 AND 1 = 1 = TRUE
if (input(IR1)==1 && input(IR3) ==1 && input(IR2)==0 && input(IR4)==0)
            {
               people_in += 1;
               lcd_gotoxy(14,1);
               printf(lcd_putc,"%3u",people_in);
            }
             while((input(IR1) && input(IR3)) ^ (input(IR2) && input(IR4)));
         }
}
   }while(1); 
}

 

[AtomSoft]

its more like:

if ((input(IR1)==0) && (input(IR3) ==0) && (input(IR2)==1) && (input(IR4)==1))

You need each check in its own Parenthesis ()

 

[Ian Rogers]

while((input(IR1) && input(IR3)) ^ (input(IR2) && input(IR4))); // (0 AND 0) = 0 (1 AND 1) = 1 0 XOR 1 = 1= TRUE

This looks ambiguous as you're looking for ALL inputs on and not what your comments imply.

Cheers Ian

 

[Mr RB]

The code is very poor, hard to understand and slow to execute.

Why not try detecting all bits at once? That's faster and much neater.

Something like this;

inputs = (PORTA & 0b00001111);  // keep only 4 bits
if(inputs == 0b00000011) blah;
if(inputs == 0b00001111) blah;