Help with PIC12508

[cbarberis]

Hi all
I seem to be going crazy with the simplest code I have ever written, but I cannot get it to work. The code is supposed to perform a very simple function: Toggle GP5 port from high to low for 20 mS and then back to high whenever a high to low transition is detected at either GP0 or GP1, That is all!!! When I program a device it seems that the output (GP5) pin is sitting at half the supply, just as if it was in a tri-state or input mode, it never toggles. I have read the data sheet and I cant see why? Perhaps there is a very simple blunder in my code, that I just can't see. The electrical connectivity is OK. The code is listed below

Thanks for your help

#include <12C508.h>
#fuses INTRC, WDT, XT, MCLR
//#rom 0x1ff={0xA00C}
#use delay(clock=4000000,RESTART_WDT)
//#define SWPWR 48
//#define EXTPWR 49
//#define PWRINT 50

#byte GPIO = 0x6
#bit SWPWR = GPIO.0
#bit EXTPWR = GPIO.1
#bit IO2 = GPIO.2
#bit RST = GPIO.3
#bit OUT4 = GPIO.4
#bit PWRINT = GPIO.5
#define ON 1
#define OFF 0
//#use fast_io(b)


void init()
{
setup_timer_0(RTCC_INTERNAL);
setup_wdt(WDT_72MS);
set_tris_b(0b00001111);
//output_high(PWRINT);
PWRINT = ON;
}


void main()
{
init();
delay_ms(50);

do{
if(!SWPWR)
{ PWRINT = OFF;
delay_ms(20);
PWRINT = ON;
delay_ms(1000); }

if(!EXTPWR)
{ PWRINT = OFF;
delay_ms(20);
PWRINT = ON;}


restart_wdt();

} while(1);

}

[PCM programmer]

I don't have the PCB compiler, but this line right here, looks
incredibly suspicious:

#fuses INTRC, WDT, XT, MCLR

You've got two oscillator settings in the #fuse statement.
I don't know what the compiler would do about that.
It might just use the XT setting, since it's the last one to
be found as the line is scanned. If you're depending on
using the internal RC oscillator, then the PIC would not run.

Get rid of one of those settings. Use either XT or INTRC,
but not both.

For a list of the oscillator configurations, look at section 8.2
of the 12C508 data sheet:
http://ww1.microchip.com/downloads/en/DeviceDoc/40139e.pdf

[Ttelmah]

[cbarberis]

It goes to show that the simplest things in life can sometimes be the most difficult! I spent hours trying to figure out why this little pic would not work. I knew it was something so stupid, that the stupid could not see. DUH!!!!

I tested it after removing the extra XT setting on the fuses and now it works fine!

Once again Thank you!

[Guest]

Hi cbarberis,

As stated by PCM Programer, the clue is in the #fuses directive.