Thread: Problem in Reading input in 16F72

I am facing some problem while reading input through PORTB in 16F72 PIC.

I wrote a simple code which shows a number between 0-9 in a seven-segment. When i press button connected to RB5, then number should increment to a different number. It works fine in Simulator. But when I tried in PIC, it shows digit 8, and have a flickering too....

Below given is my source code written in HiTech C. Please help. I am stuck with this problem for a long perios....

//include file
#include <pic.h>

//16F72 configuration word according to the features required.
__CONFIG(0x3FB1);

int i;

// This macro is to make a delay after showing a digit in a segment.
#define my_delay() for ( i = 0; i <= 20; i++ );

void showNumber ( unsigned char *num )
{
switch ( (*num) )
{
case 0:
PORTC = 0b11111100;
PORTB = 0b00000000;
break;
case 1:
PORTC = 0b00011000;
PORTB = 0b00000000;
break;
case 2:
PORTC = 0b01101100;
PORTB = 0b00000001;
break;
case 3:
PORTC = 0b00111100;
PORTB = 0b00000001;
break;
case 4:
PORTC = 0b10011000;
PORTB = 0b00000001;
break;
case 5:
PORTC = 0b10110100;
PORTB = 0b00000001;
break;
case 6:
PORTC = 0b11110100;
PORTB = 0b00000001;
break;
case 7:
PORTC = 0b00011100;
PORTB = 0b00000000;
break;
case 8:
PORTC = 0b11111100;
PORTB = 0b00000001;
break;
case 9:
PORTC = 0b10111100;
PORTB = 0b00000001;
break;
case 10:
PORTC = 0b0;
PORTB = 0b0;
PORTA = 0b0;
break;
}
}

//main function
void main ( void )
{
unsigned int noShow = 10;
unsigned int temp = 0;

unsigned long swith_1_Count = 0;
unsigned int flag1 = 0;

TRISB = 0b00100000;
TRISA = 0x00;
TRISC = 0x00;

PORTC = 0;
PORTB = 0;
PORTA = 0;

while ( 1 )
{
if ( ( PORTB & 0b00100000 ) == 0b00100000 )
{
temp = ( temp +1 ) % 10;
}

PORTA = 0b00000001;
showNumber(&temp);
my_delay();
}
}

I would guess that it is showing all numbers very fast and so it looks like an 8. Try increasing your delay lots.

Also, use the correct labels for the config. No one knows what CONFIG(0x3FB1); does.

Mike.

Thanks for your reply..

Its not showing all numbers very fast. even if i increase my delay it seems to be like that... But still according to the source code, how will it behaves like this?

Now here one basic doubt...

Can i use some of the pins in PORTB as Input and some of the pins in PORTB as output at the same time?...
This problem happens when i am doing so...
Please help

Yes, you can set any combination of input/output.

Mike.

Hi eng1, thanx for your reply. I am new to PIC. Can u brief on wat is software de-bouncing or could pls give any link abt this... ?