PIC C18 External Interrupts INT0

[natraj20]

Hello guys,

Problem with the very basics.
I am stuck with the external interrupt INT0 at RB0.
Controller - PIC 18F47J53
MPLAB IDE, Microchip C Compiler

I could not figure out what is wrong with the following code. Kindly help me out to make this work!!

#include <p18f47j53.h>
#include <delays.h>
#include <portb.h>

#pragma config OSC = HS
#pragma config WDTEN = OFF
#pragma config XINST = OFF

void InterruptServiceHigh(void);
void InterruptServiceLow(void);

int x;

void main(void)
{

INTCONbits.INT0IF = 0;
INTCONbits.INT0IE = 1;
INTCON2bits.INTEDG0 = 1;

INTCON2bits.RBPU = 0;
//EnablePullups();

TRISE = 0;
TRISBbits.TRISB0 = 1;

RCONbits.IPEN = 1;
INTCONbits.GIE = 1;
INTCONbits.PEIE = 1;

while(1)
{
PORTE = 0x01;
}

}


// High priority interrupt vector

#pragma code InterruptVectorHigh = 0x08
void InterruptVectorHigh(void)
{
_asm
goto InterruptServiceHigh
_endasm
}


// Low priority interrupt vector

#pragma code InterruptVectorLow = 0x18
void InterruptVectorLow(void)
{
_asm
goto InterruptServiceLow
_endasm
}



// Interrupt Service Routine

// Interrupt pragma for high priority

#pragma code
#pragma interrupt InterruptServiceHigh
void InterruptServiceHigh()
{
// function statements

if(INTCONbits.INT0IF)
{
x = 0;

while(x <= 2)
{
PORTE = 0x01;

Delay10KTCYx(120); // Delay of 1 sec with 12 MHz

PORTE = 0x02;

Delay10KTCYx(120);

x++;
}
INTCONbits.INT0IF = 0;
}

// return from high priority interrupt

}


// Interrupt pragma for low priority

#pragma code
#pragma interrupt InterruptServiceLow
void InterruptServiceLow()
{
// function statements

// return from low priority interrupt

}

 

[BeeBop]

Hello guys,

Problem with the very basics.
I am stuck with the external interrupt INT0 at RB0.
Controller - PIC 18F47J53
MPLAB IDE, Microchip C Compiler

I could not figure out what is wrong with the following code. Kindly help me out to make this work!!

#include <p18f47j53.h>
#include <delays.h>
#include <portb.h>

#pragma config OSC = HS
#pragma config WDTEN = OFF
#pragma config XINST = OFF

void InterruptServiceHigh(void);
void InterruptServiceLow(void);

int x;

void main(void)
{

    INTCONbits.INT0IF = 0;
    INTCONbits.INT0IE = 1;
    INTCON2bits.INTEDG0 = 1;

    INTCON2bits.RBPU = 0;
    //EnablePullups();

    TRISE = 0;
    TRISBbits.TRISB0 = 1;

    RCONbits.IPEN = 1;
    INTCONbits.GIE = 1;
    INTCONbits.PEIE = 1;

    while(1)    
    {
        PORTE = 0x01;
    }

}


//  High priority interrupt vector

#pragma code InterruptVectorHigh = 0x08
void InterruptVectorHigh(void)
{
    _asm
    goto InterruptServiceHigh
    _endasm
}


//  Low priority interrupt vector

#pragma code InterruptVectorLow = 0x18
void InterruptVectorLow(void)
{
    _asm
    goto InterruptServiceLow
    _endasm
}



//  Interrupt Service Routine

// Interrupt pragma for high priority

#pragma code
#pragma interrupt InterruptServiceHigh
void InterruptServiceHigh()
{
    // function statements

    if(INTCONbits.INT0IF)
    {
        x = 0;
            
        while(x <= 2)
            {
                PORTE = 0x01;
            
                Delay10KTCYx(120);    // Delay of 1 sec with 12 MHz
            
                PORTE = 0x02;
        
                Delay10KTCYx(120);
            
                x++;
            }
        INTCONbits.INT0IF = 0;
    }

    // return from high priority interrupt

}


//  Interrupt pragma for low priority

#pragma code
#pragma interrupt InterruptServiceLow
void InterruptServiceLow()
{
    // function statements

    // return from low priority interrupt

}

I placed your source between code tags (Use the # key when you post. It keeps your formatting, so it is easier to read your code.

I didn't take a close look, but one thing which jumped out was that you are calling a delay from your interrupt service routine. That isn't a good habit to get into, and often makes a program fail.
The preferred way to do this it to set a flag variable in the ISR, and check for that flag in your endless loop. ie: while(1){ if(interrupt_flag) do what i want; call as many delays as I want;}
regards

EDIT: You may find that flashing just a single LED as a subroutine, from within main is a good debugging technique. You can put the call to it most anywhere to know if the chip gets to it.

 

[Wond3rboy]

Here is your code. You missed to put in values if ANCON0 and ANCON1 to configure the pins as digital(datasheet page 371).

#include <p18f47j53.h>
#include <delays.h>
#include <portb.h>

#pragma config OSC = HS
#pragma config WDTEN = OFF
#pragma config XINST = OFF

void InterruptServiceHigh(void);
void InterruptServiceLow(void);

int x;

void main(void)
{
	[B][COLOR="red"]ANCON1=0xff// sets all Analog 
	ANCON0=0xff;//pins as digital[/COLOR][/B]
    INTCONbits.INT0IF = 0;
    INTCONbits.INT0IE = 1;
    INTCON2bits.INTEDG0 = 1;

    INTCON2bits.RBPU = 0;
    //EnablePullups();

    TRISE = 0;
    TRISBbits.TRISB0 = 1;

    RCONbits.IPEN = 1;
    INTCONbits.GIE = 1;
    INTCONbits.PEIE = 1;

    while(1)    
    {
        PORTE = 0x01;
    }

}


//  High priority interrupt vector

#pragma code InterruptVectorHigh = 0x08
void InterruptVectorHigh(void)
{
    _asm
    goto InterruptServiceHigh
    _endasm
}


//  Low priority interrupt vector

#pragma code InterruptVectorLow = 0x18
void InterruptVectorLow(void)
{
    _asm
    goto InterruptServiceLow
    _endasm
}



//  Interrupt Service Routine

// Interrupt pragma for high priority

#pragma code
#pragma interrupt InterruptServiceHigh
void InterruptServiceHigh()
{
    // function statements

    if(INTCONbits.INT0IF)
    {
        x = 0;
            
        while(x <= 2)
            {
                PORTE = 0x01;
            
                Delay10KTCYx(120);    // Delay of 1 sec with 12 MHz
            
                PORTE = 0x02;
        
                Delay10KTCYx(120);
            
                x++;
            }
        INTCONbits.INT0IF = 0;
    }
}




//  Interrupt pragma for low priority

#pragma code
#pragma interrupt InterruptServiceLow
void InterruptServiceLow()
{
    // function statements

    // return from low priority interrupt
}