PIC24 and #INT_EXT1

[soonc]

I tried setting up to use external interrupt but it does not interrupt !

I change the code to use INT0 which is not a #pin_select pin and it works just fine.

What did I do wrong with this code ?

Thanks for any help.

Compiler V5.047

[Ttelmah]

As posted, it works.....

There are a couple of comments:
Use:

[benoitstjean]

I use the PIC24HJ256GP206 and a bunch of different interrupts (serial, external pins, timers etc).

From your short message, *I think* what you're trying to do will not work but there's another alternative. You haven't provided much details but I will answer based on what I read in your post.

What I can see from your code is that you're trying to obtain some external hardware interrupts, but on serial pins F4/F5. That, I believe, will not work.

From what I have tried, external interrupts can only be triggered on pins B0, F6 (INT0), D8 (INT1), D9 (INT2), D10 (INT3) and D11 (INT4), that's it (at least that's what I use). For pins F6, D8-D11, you also need to specify on which edge you want to trigger.

For pin B0, you must add the following flag such as:

enable_interrupts( INTR_CN_PIN | PIN_B0 );

That will specify that PIN_B0 is an interrupt-on-change pin.

Then for the other pins, my code is too big to post here but I believe that this is what you need (this is a copy-paste from my code):

In your .h:

#define PIN_INT_ON_CHG PIN_B0
#define PIN_INPUT_0 PIN_F6
#define PIN_INPUT_1 PIN_D8
#define PIN_INPUT_2 PIN_D9
#define PIN_INPUT_3 PIN_D10
#define PIN_INPUT_4 PIN_D11


In your .c:

ext_int_edge( 0, H_TO_L );
ext_int_edge( 1, H_TO_L );
ext_int_edge( 2, H_TO_L );
ext_int_edge( 3, H_TO_L );
ext_int_edge( 4, H_TO_L );

enable_interrupts( INTR_CN_PIN | PIN_INT_ON_CHG );
enable_interrupts( INT_EXT0 );
enable_interrupts( INT_EXT1 );
enable_interrupts( INT_EXT2 );
enable_interrupts( INT_EXT3 );
enable_interrupts( INT_EXT4 );


Then in some other file:

#INT_CNI
void PIN_INT_ON_CHG_ISR( void )
{
// Put your code here
}

#INT_EXT0
void INT_EXT_INPUT0( void )
{
// Put your code here
}

#INT_EXT1
void INT_EXT_INPUT1( void )
{
// Put your code here
}

#INT_EXT2
void INT_EXT_INPUT2( void )
{
// Put your code here
}

#INT_EXT3
void INT_EXT_INPUT3( void )
{
// Put your code here
}

#INT_EXT4
void INT_EXT_INPUT4( void )
{
// Put your code here
}


If you want to get fancy and trigger off every edge like I do, everytime you get an interrupt on a pin, then in the #INT_EXTx function, you toggle the ext_int_edge( 0, H_TO_L ) (high-to-low) to ext_int_edge( 0, L_TO_H ) (low-to-high). You set yourself a flag that gets toggled such as:

#INT_EXTx
void INT_EXT_INPUTx( void )
{
if( IsInputxLtoH == TRUE )
{
IsInputxLtoH = FALSE;
ext_int_edge( x, H_TO_L );
}
else
{
IsInput0LtoH = TRUE;
ext_int_edge( x, L_TO_H );
}

However, since you're trying to interrupt on the serial pins, then why not just use the serial interrupts like this:

#INT_RDA
void INT_SerialRX( void )
{
char = fgetc( PCom1 );
}

I've been using the above code for 2 years and it works fine. The #INT_RDA will get triggered upon every received character. You need some way to handle the characters and queue-them up in some message queue.

I've never bothered using the #INT_TBA interrupt for character transmission because I don't care to know if a character has been transmitted or not (plus I use DMA transfers for serial transmission so that's very fast).

As for the external interrupt pins, I get an interrupt every time the pin changes state.

Hope this helps, you haven't provided much details.

I think if you search for my posts, you will find one that talks about external interrupt pins. Hope this helps.

[soonc]

[Ttelmah]

I must admit with BGA, and high density SM packages, I've learnt to 'always' be suspicious that the pin actually is doing what you expect. GND!... Eeekl.

At least it was an obvious answer.

[soonc]

Thanks. The code works, it was my silly mistake.