BoostC Flaw?

[AtomSoft]

I wrote this simple code

#include <system.h>

#pragma DATA	_CONFIG1H, _INTIO1_OSC_1H
#pragma DATA	_CONFIG2L, _BOR_OFF_2L     
#pragma DATA	_CONFIG2H, _WDT_OFF_2H    
#pragma DATA	_CONFIG4L, _LVP_OFF_4L

#pragma	CLOCK_FREQ 8000000

void main(void)
{
    set_bit( osccon, IRCF2 );           //8 MHz
    set_bit( osccon, IRCF1);
    set_bit( osccon, IRCF0 );

	trisb=0;
    trisa=0;
    porta=0;
    portb=0;

    porta.1=1;
    delay_s(2);
    porta.2=1;

	while(1){

	}
	
}

Yet it doesnt work right. Im worried it might give me a issue later on. What it does it light led 1 on RA1 then led 2 on RA2 but once it lights led 2 LED 1 turns off.

How come?

 

[futz]

#pragma DATA	_CONFIG1H, _INTIO1_OSC_1H

You probably meant to use _INTIO2_OSC_1H. Using INTIO1 loses you the RA6 pin as a usually useless clock output.

    set_bit( osccon, IRCF2 );           //8 MHz
    set_bit( osccon, IRCF1);
    set_bit( osccon, IRCF0 );

That's fine, but these can also be done with either

    osccon,IRCF0=1;
    osccon,IRCF1=1;
    osccon,IRCF2=1;

or

    osccon=0x72;

These can be simplified if you want

	trisa=trisb=0;
        porta=portb=0;

And this can be simplified too

	while(1);

Yet it doesnt work right. Im worried it might give me a issue later on. What it does it light led 1 on RA1 then led 2 on RA2 but once it lights led 2 LED 1 turns off.

How come?

Not sure. Is this on Junebug? Show me your circuit.

Probably nothing to do with it, but your "porta.1=1" and such should be "lata.1=1". Use the latch/shadow registers instead of the ports and you'll avoid weird problems later.

 

[AtomSoft]

wow wierd i did this:

#include <system.h>

#pragma DATA	_CONFIG1H, _INTIO2_OSC_1H
#pragma DATA	_CONFIG2L, _BOR_OFF_2L     
#pragma DATA	_CONFIG2H, _WDT_OFF_2H    
#pragma DATA	_CONFIG4L, _LVP_OFF_4L

#pragma	CLOCK_FREQ 8000000

void main(void)
{
    osccon=0x72;           //8 MHz

	trisb=trisa=0;
    porta=portb=0;

    lata.1=1;
    delay_s(1);
    lata.2=1;

	while(1){

	}
	
}

works fine now...

 

[futz]

wow wierd i did this:
works fine now...

So it's happy with lata.1/2, but not with porta.1/2? How strange! Oh well, you should be using the LAT's anyway on 18F's.

 

[AtomSoft]

yeah its pretty wierd but as long as it works. ill be sure to use lata for pic18F from now on. by the way im away from home and am writing this on a psp.

 

[kchriste]

Are you using current limiting resistors on the LEDs? If not, it is possible that the Read/Modify/Write instruction won't work properly using the porta register. Using lata is the preferred method anyway. Which PIC are you using? Some pins are TTL level and others are Schmitt Trigger level pins.

 

[AtomSoft]

it was happening on 2 PICs. My Junebug(18F1320) and a 18F248. But all is well and im happy lol

edit: also i due have 2 resistors on it. (100ohm)

 

[kchriste]

If you want, measure the voltage on the pins driving the LEDs when the LEDs are on. If it is equal or less than 2V, then that was the problem but with the 100Ω resistors it should be above 2V according to the spec sheet.