problem in reading port value

Thread Starter

Ahmed Adel

Joined May 12, 2008
18
hi everybody ..
I have button connected to RA0 of PORTA via pull down resistor and an LCD that I want to show the word "ONE" if button is pressed and show "Zero" if the button isn't pressed .. I am using mikroC and this is my code .. this code isn't operational .. I get "Zero" all the time regardless of button status

Rich (BB code):
// LCD module connections
sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;

sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections




void main() {


TRISB=0x00;
TRISA=0xFF;


Lcd_Init();
Lcd_Cmd(_LCD_CLEAR);
Lcd_Cmd(_LCD_CURSOR_OFF);

while (1)
{
     if (PORTA.F0==1)      
     {
        Lcd_Cmd(_LCD_CLEAR);
        Lcd_out(1,1,"ONE");

        delay_ms(1000);
     }
     else
     {
        Lcd_Cmd(_LCD_CLEAR);
        Lcd_out(1,1,"Zero");
        delay_ms(1000);

       }
     

}

}
 
Last edited:

AlexR

Joined Jan 16, 2008
732
You don't say which PIC you are using but in any case portA on most PICs can be configured as either an analogue port or a digital port. It defaults to analogue whereas your application needs it to be a digital port.
To make it digital you have to turn off any AtoD functions and/or any comparator function assosiated with the port.
Take a look at the data sheet for your chip to see what registers need to be set.
 

mik3

Joined Feb 4, 2008
4,843
In your code you have:

if (PORTA.F0==1)

I think it should be like that:

if (PORTA.A0==1)

or try

if (pin_A0==1)
 
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