Having trouble with PORTB and A (need help)

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qmriso

Joined: 30 Nov 2006
Posts: 81
Helped: 1

07 Dec 2006 7:39 Having trouble with PORTB and A (need help)

I am currently working on simple UART project, but when i recive a byte on portB ( i'm using PIC 18f2320) pin RB5 never gives an output
even if i send 0xFF.
So I thought to test the port by using this code

void main(void)
{
TRISB=0;
LATB=0;

while (1)
{
LATB=0xFF;
}
}

But no luck.(MPLAB said that this would work fine)
So i tried to use PORTA with this code:

void main(void)
{
ADCON1bits.PCFG3=1; //sets portA bit0-3 to digital I/O

TRISA=0;
LATA=0;

while (1)
{

LATA=0xFF;
}

}
Again MPLAB said that this would work fine, but on the chip i had nothing on pins RA7 and RA4 (i have configered the oscillator so that RA 6 and 7 are I/O)

Can anyone Help me?

traxonja

Joined: 06 Apr 2004
Posts: 109
Helped: 1

07 Dec 2006 14:05 Re: Having trouble with PORTB and A (need help)

Check the datasheet for that MCU that you are using. Usually PORTA.4 cannot be used as output, so check the PDF.

www.elektronika.ba

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07 Dec 2006 14:05 Ads

En_Serg

Joined: 22 Dec 2004
Posts: 11

10 Dec 2006 4:59 Re: Having trouble with PORTB and A (need help)

CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)

OSC<3:0>: Oscillator Selection bits
bit 3-0 FOSC
0101 = EC oscillator, port function on RA6

You need set theese bits in CONFIG1H for correct work with RA6