> OK, this is just getting weird...
>=20
> I had external interrupts working in the JAL prototype of my=20
> remote-control receiver code, but I'm rewriting it in C18 (mainly=20
> because I can do floating-point calculations for timer preload and=20
> threshold values; JAL AIUI only handles integer math).
>=20
> The thing is, I'm not seeing any interrupts -- none at all. I put a=20
> breakpoint on the "goto ISR" line, and the PIC didn't break. I also=20
> didn't see anything on the logic analyser....
>=20
> I must be doing something stupid, but I can't for the life of me figure=20
> out what:
>=20
> #include <p18cxxx.h>
> #pragma config OSC =3D HS     // High Speed Crystal oscillator
> #pragma config WDT =3D OFF    // Watchdog timer off
> #pragma config LVP =3D OFF    // Low-voltage programming off
> #pragma config MCLRE =3D ON   // MCLR (reset) on
> #pragma config FSCM =3D OFF   // Failsafe clock monitor off
>=20
> // timer0 prescaler settings
> #define TIMER0_USE_PRESCALER
> #define TIMER0_PRESCALER_SETTING 5
>=20
> // Infra-red receiver
> #define PIN_IR                PORTBbits.RB0
> #define PIN_IR_DIR            TRISBbits.TRISB0
>=20
> void isr(void);
>=20
> // ISR stub code
> #pragma code HIGH_INTERRUPT_VECTOR =3D 0x8
> void high_ISR (void)
> {
>      _asm
>          goto isr
>      _endasm
> }
> #pragma code
>=20
> // Interrupt Service Routine
> #pragma interrupt isr
> void isr(void)
> {
>      unsigned char tval;
>      char overflow;
>=20
>      // Store timer value and overflow flag and rearm the timer
>      tval =3D TMR0L;
>      TMR0L =3D 0;
>      overflow =3D INTCONbits.TMR0IF;
>      INTCONbits.TMR0IF =3D 0;
>=20
>      // detect RB0 int flag
>      if (INTCONbits.INT0IF) {
>          char pol;
>=20
>          // clear interrupt flag
>          INTCONbits.INT0IF =3D 0;
>=20
>          // store bit polarity, then flip to other polarity
>          pol =3D INTCON2bits.INTEDG0;
>          INTCON2bits.INTEDG0 =3D !INTCON2bits.INTEDG0;
>      }
> }
>=20

The TMR0 part in the interrupt routine is always executed even if the inter=
rupt=20
source is RB0. But maby that is the intention?

/Ruben

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
Ruben J=F6nsson
AB Liros Electronic
Box 9124, 200 39 Malm=F6, Sweden
TEL INT +46 40142078
FAX INT +46 40947388
ruben@pp.sbbs.se
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

--=20
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