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huma
Joined: 23 Jun 2006
Posts: 12
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| Interrupt problem |
 Posted: Wed Jul 12, 2006 6:15 am |
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hello,
I m trying to toggle the LED's connected to PORTD of PIC 16F877 based on interrupt from RB0/INT pin when a push button is pressed.
I am simulating this program in Proteus VSM,but i m getting no result.Nothing happens when i push the button and it is also not showing the normal sequence i.e in While loop.
Is there any problem with my code?
I have checked the other topics related to RB0/INT interupt,but everything seems to me ok,i might have missed something and i m not getting whats that.
Please tell me i shall be very thankful to you.
| Code: | /*
The program toggles the LED's on/off connected on PORTD when push button is pressed,
causing interrupt on RB0/INT pin
*/
#include "16f877.h"
#fuses XT,NOWDT
#use delay(clock = 4000000)
//---------function prototypes
#int_ext
void external_int_isr(void);
//----------------------------
//---------global variables---
char value = 0xbb;
//----------------------------
void main()
{
set_tris_d(0x00); //LED's connected to portD ,make it output port
set_tris_b(0x01); //set RB0 = 1
port_b_pullups(TRUE);
ext_int_edge(H_TO_L);
enable_interrupts(INT_EXT);
enable_interrupts(GLOBAL);
while(true)
{
output_d(value); //output a sequnce on PORTD
}
}
void external_int_isr(void)
{
value = ~value; //complement the sequence
clear_interrupt(int_ext); //clear the INTF flag bit
}
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Ttelmah
Guest
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| Re: Interrupt problem |
| Posted: Wed Jul 12, 2006 7:03 am |
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Comments in the code.
| Code: | /*
The program toggles the LED's on/off connected on PORTD when push
button is pressed, causing interrupt on RB0/INT pin
*/
#include "16f877.h"
#fuses XT,NOWDT
#use delay(clock = 4000000)
//---------function prototypes
//#int_ext
void external_int_isr(void);
//--- Do _not_ prototype with the interrupt definition - this _must_ be
//--- on the real routine.
//----------------------------
//---------global variables---
char value = 0xbb;
//----------------------------
void main()
{
//set_tris_d(0x00); //LED's connected to portD ,make it
// output port
//set_tris_b(0x01); //set RB0 = 1
//--- The two TRIS statements, actually do nothing. Since you are in
//--- 'standard_io' mode, the compiler will override the TRIS, as soon
//--- as you perform IO. Does not matter, but if you want manual control
//--- of TRIS, select 'fast_io' mode for the ports.
port_b_pullups(TRUE);
ext_int_edge(H_TO_L);
enable_interrupts(INT_EXT);
enable_interrupts(GLOBAL);
while(true)
{
output_d(value); //output a sequnce on PORTD
}
}
#int_ext
//You _must_ have the interrupt defintion line here
void external_int_isr(void)
{
value = ~value; //complement the sequence
//clear_interrupt(int_ext); //clear the INTF flag bit
//Do not do this. The compiler already does it for you
}
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The problem that is stopping it working, is that there isn't a real interrupt handler, because of the wrong placement of the #int definition.
Best Wishes |
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huma
Joined: 23 Jun 2006
Posts: 12
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| Thanks |
| Posted: Wed Jul 12, 2006 12:36 pm |
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thanks a lot Ttelmah.it worked i just did as u said.
and i also come to know whts this Standard and fast io are.Thanks. |
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