Well I thought I had finally finished my trigger project, but after
unsoldering the test points and soldering back in the resistor, it
ceased working.

After some investigation I had soldered everything back together with it
turned on, I had also gotten a bridged joint. Needless to say I wanted
to test the PIC. I wrote the attached ASM to basically oscillate the
outputs and give me something to look at on the scope. I am expecting to
see a square wave...

The test circuit is literally VDD to +5v and VSS to 0v, nothing else. I
was going to use the internal osc for this.

Could someone take a look at it and tell me if my code might work at
what I am trying, thanks...


        title "PIC16F627 e-trigger"
        list p=16f627,f=inhx32
#include <p16f627.inc>

    __CONFIG _INTRC_OSC_NOCLKOUT & _WDT_OFF & _BODEN_OFF & _CP_OFF &
_DATA_CP_OFF & _LVP_OFF & _MCLRE_OFF

    CBLOCK 0x20
rolls
state
    ENDC

    org 00h
    goto Start
    org 04h

    BCF INTCON,T0IF ;clear the flag

    DECFSZ rolls,1
    GOTO END_INT

    BTFSC state,0
    GOTO TURN_OFF
TURN_ON
    BSF state,0
    MOVLW 0xFF
    MOVWF PORTA
    MOVWF PORTB

    GOTO END_INT
TURN_OFF
    BCF state,0
    MOVLW 0
    MOVWF PORTA
    MOVWF PORTB

END_INT
    RETFIE

Start

    ; turn off the comparators
    MOVLW 0x07
    MOVWF CMCON

        ; switch to bank 1 to affect the TRIS registers
    BCF STATUS,RP1
    BSF STATUS,RP0 ;select bank1


        ; set A and B as outputs
    MOVLW 0x00
    MOVWF TRISA
    MOVWF TRISB
    ; Make the timer a timer not a counter...
    BCF OPTION_REG,T0CS
    ; Back to bank 0
    BCF STATUS,RP0

    MOVLW 0
    MOVWF rolls
    MOVWF state
    ; enable tmr0 interrupts

    BSF INTCON,T0IE
    ; turn them on
    BSF INTCON,GIE

    ; enter an endless loop, here we go to interrupt
    ; based operation.
LOOP

    GOTO LOOP

    END

--
Anthony Toft <toftat@cowshed.8m.com>

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