On Fri, 6 Nov 1998, Ultra Control Sdn. Bhd. wrote:

> Anyone for the old Debouce challege:
>
> I hooked a push to make switch at RA1 of a PIC16F84.
> The other end to the ground. And connected to the +VDD is a 15KOhm
> resistor.
> What is the fool proof way to read the key? I used the code below with
> inconsistent result although is does work. Or any recommendation of a
> cheap hardware
> configuration. WWW site welcome.
>
> SCAN      MOVLW 0XFF               ;Init Port A as input
>                  TRIS PORTA                  ;
>
> KEY_LO  BTFSC   PORTA, 1        ;Key Press down = 0
>                  GOTO KEY_LO             ;Keep scan till LO detected
>                  CALL DELAY                 ;Debouce, dont scan for
> ~500msec
>                  CALL DELAY                 ;
>                  CALL DELAY                 ;
>                  CALL DELAY                 ;
> KEY_RLS  BTFSS PORTA, 1           ;Key Release
>                    GOTO KEY_RLS

I'm not sure what you're seeking, but you oughta check out my web page:


http://www.interstice.com/~sdattalo/technical/software/pic/debounce.html

It's better suited for simultaneously debouncing 8 inputs.

Scott