16F676 Interupt on Change pin determination

[BGreen]

Melanie helped with some example code in this thread http://www.picbasic.co.uk/forum/showthread.php?t=3589
and I figure I'm still confused somewhere in the setup. I defines both "OldPorta" and "NewPorta" which I THINK was the way to start it but when I get the interupt it just defaults to the operation for Porta.5. The following program was supposed to do the following.

If pin Porta.5 is interupted an led would blink 4 times. Porta.4, 3 times, Porta.3, 2 times. Every time it is interupted it blinks 4 times no matter which pin. I can't seem to figure out, probibly from inexperience, what I'm doing wrong. If someone could help I'd appriciate it.


@ DEVICE PIC16F676,INTRC_OSC_NOCLKOUT,WDT_ON,PWRT_OFF,BOD_O FF,PROTECT_OFF,CPD_OFF,MCLR_OFF
ANSEL = 0 ' DISABLE THE ANALOG INPUT
CMCON = 7 ' DISABLE COMPARATOR ON PORTA
VRCON = 0 ' A/D Voltage reference disabled
TRISA = %00111110 ' SETS ALL PORTA PINS TO INPUT ' Set PORTAA to all input
WPUA = %00000110
SYMBOL LED = PORTA.0
I VAR WORD
OLDPORTA VAR WORD
NEWPORTA VAR WORD
INTCON = %10000000
IOCA = %00111000
OPTION_REG = %00001000
OUTPUT PORTA.0
LOW LED
PAUSE 1000
HIGH LED
GOTO BASE
MYINT:
NEWPORTA = PORTA
INTCON = %10000000
IF NEWPORTA.5 <> OLDPORTA.5 THEN
ILOOP:
I = I + 1
IF I = 5 THEN
resume BASE
ENDIF
LOW LED
PAUSE 1000
HIGH LED
PAUSE 1000
GOTO ILOOP
ENDIF
IF NEWPORTA.4 <> OLDPORTA.5 THEN
I = I + 1
IF I = 4 THEN
resume BASE
ENDIF
LOW LED
PAUSE 1000
HIGH LED
PAUSE 1000
GOTO ILOOP
ENDIF
IF NEWPORTA.3 <> OLDPORTA.5 THEN
I = I + 1
IF I = 3 THEN
resume BASE
ENDIF
LOW LED
PAUSE 1000
HIGH LED
PAUSE 1000
GOTO ILOOP
ENDIF
BASE:
OLDPORTA = PORTA
I = 0
ON INTERRUPT GOTO MYINT:
INTCON = %10001000
LOOP:
SLEEP 240
GOTO LOOP

[Archilochus]

Hi HH,
Just at a quick glance, it looks like these two lines are off a bit:


IF NEWPORTA.4 <> OLDPORTA.5 THEN < compares A.4 to A.5

IF NEWPORTA.3 <> OLDPORTA.5 THEN < compares A.3 to A.5


I think they should be:

IF NEWPORTA.4 <> OLDPORTA.4 THEN

IF NEWPORTA.3 <> OLDPORTA.3 THEN

Arch

[BGreen]

Sorry arch, I edited it to simplify it and may have messed that up. Let me check it and I'll post again.

[BGreen]

I fixed it and it still does the same thing. In addition, it seems that if I even get close to it sometimes it goes off. Is there a pin I should ground or have I really screwed something up?

[Archilochus]

I tossed the code into MicroCode Studio to get a better look - think I see the problem...

	IF NEWPORTA.5 <> OLDPORTA.5 THEN
ILOOP:
		I = I + 1
		IF I = 5 THEN
			resume BASE
		ENDIF
		LOW LED : PAUSE 1000 : HIGH LED
		PAUSE 1000
		GOTO ILOOP
	ENDIF

	IF NEWPORTA.4 <> OLDPORTA.4 THEN
		I = I + 1
		IF I = 4 THEN
			resume BASE
		ENDIF
		LOW LED : PAUSE 1000 : HIGH LED
		PAUSE 1000
		GOTO ILOOP  ; <<<<<<<<<< JUMPS BACK TO Iloop
	ENDIF

No matter which pin is interrupted, the code jumps back to "Iloop", which is in the middle of the "IF NEWPORTA.5 <> OLDPORTA.5 THEN" test. It loops there until done, blinking the LED as if A.5 were interrupted, no matter which pin actually caused it.

Arch

PS - on the erratic triggering, make sure your programmer is actually setting MCLR off, and check for 'floating' inputs.
What value pullup/pulldowns are you using?

[BGreen]

I wasn't using anything but internals on this Arch. I'll check out what you posted and give it a whirl. Thanks for the help. I think my brain began to die after I passed 50.