On 5 Aug 2005 11:02:17 -0700, the renowned StephensDigital@gmail.com
wrote:

>
>1. shawnb_...@yahoo.com 	  Aug 5, 10:53 am     show options
>Newsgroups: comp.arch.embedded
>From: shawnb_...@yahoo.com - Find messages by this author
>Date: 5 Aug 2005 10:53:59 -0700
>Local: Fri, Aug 5 2005 10:53 am
>Subject: PIC18 Interrupts
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>Hello all.  I'm a newbie in the realm of micro programming.  I'm using
>MPLAB C18 with the PIC18F452 and PICDEMO 2 Plus board.  I can't, for
>the life of me, figure out how to do an interrupt routine!
>  I've used the buzzer interrupt sample that came with the ICD2
>software, but have been unable to modify it to suit my needs.  What I
>want to do is wait for a button to be pressed to start my routine.  Can
>someone please help?
>
>
>Well, the PIC18XX family has a wealth of interrupt sources including
>interrupt on PORT(B?) value change which would probably work for your
>button press. CHeck out Microchip's website. There are scads of
>application notes on stuff like this.
>
>
>Bob Stephens

Also get yourself a copy of the "PICmicro� 18C MCU Family
Reference Manual", which presents the information slightly differently
and in more detail relative to the datasheets. It's a bit more complex
than the lower end PICs because of the multiple priority interrupts,
but it is still pretty straightforward once you understand it.  

By the way, I don't much like your idea of triggering an interrupt off
of a switch unless you really need to do it (for example to come out
of sleep on change).  I'd rather see you polling the switch from a
timer-driven periodic interrupt. 


Best regards, 
Spehro Pefhany
-- 
"it's the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

I've been trying, but I guess I don't know what to look for.  I feel
like the code I'm writing should work.  Would you take a look and tell
me why it doesn't?

This program is simple...wait for the button press, then turn on all of
PORTC.

#include <p18f452.h>  /* for the special function register declarations
*/
#include <portb.h>    /* for the RB0/INT0 interrupt */

#pragma config OSC = HS
#pragma config WDT = OFF
#pragma config LVP = OFF
#pragma config DEBUG = ON

void toggle_light (void);

#pragma code HIGH_INTERRUPT_VECTOR = 0x8
void high_ISR(void)
{
	_asm
		goto toggle_light
	_endasm
}
#pragma code

#pragma interrupt toggle_light
void toggle_light (void)
{
	TRISC=0;
	PORTC=255;
}

void EnableHighInterrupts (void)
{
  RCONbits.IPEN = 1;         /* enable interrupt priority levels */
  INTCONbits.GIEH = 1;       /* enable all high priority interrupts */
}

void main(void){
EnableHighInterrupts();
OpenRB0INT (PORTB_CHANGE_INT_ON & /* enable the RB0/INT0 interrupt */
              PORTB_PULLUPS_ON &    /* configure the RB0 pin for input
*/
              FALLING_EDGE_INT);    /* trigger interrupt upon S3 button
                                       depression */
CCP1CON = 0x0F;
while(1);
}

1. shawnb_...@yahoo.com 	  Aug 5, 10:53 am     show options
Newsgroups: comp.arch.embedded
From: shawnb_...@yahoo.com - Find messages by this author
Date: 5 Aug 2005 10:53:59 -0700
Local: Fri, Aug 5 2005 10:53 am
Subject: PIC18 Interrupts
Reply | Reply to Author | Forward | Print | Individual Message | Show
original | Report Abuse

Hello all.  I'm a newbie in the realm of micro programming.  I'm using
MPLAB C18 with the PIC18F452 and PICDEMO 2 Plus board.  I can't, for
the life of me, figure out how to do an interrupt routine!
  I've used the buzzer interrupt sample that came with the ICD2
software, but have been unable to modify it to suit my needs.  What I
want to do is wait for a button to be pressed to start my routine.  Can
someone please help?


Well, the PIC18XX family has a wealth of interrupt sources including
interrupt on PORT(B?) value change which would probably work for your
button press. CHeck out Microchip's website. There are scads of
application notes on stuff like this.


Bob Stephens

Hello all.  I'm a newbie in the realm of micro programming.  I'm using
MPLAB C18 with the PIC18F452 and PICDEMO 2 Plus board.  I can't, for
the life of me, figure out how to do an interrupt routine!
  I've used the buzzer interrupt sample that came with the ICD2
software, but have been unable to modify it to suit my needs.  What I
want to do is wait for a button to be pressed to start my routine.  Can
someone please help?