16F690 Pin Interrupt

[Anobium]

I have a 16F690.

I have a tactile switch on RA3.  This is the Microchip demo board.

How do I raise an interrupt on RA3?

My current code is.

#chip 16F690, 4
#config Osc = XT, MCLRE_OFF
'Set the input pin direction
    #define SwitchIn1 PORTa.3
    Dir SwitchIn1 In
#define LedPort PORTc
DIR PORTC OUT
'Set the input pin direction
Dir PORTA.0 In
dim ADCreading as word
dim ccount as byte
dim leddir as byte
ccount = 8
leddir = 1
On Interrupt PORTABChange  Call Setir
main:
    ADCreading = ReadAD(AN0)

        Set PortC = ccount

        if leddir = 0 then 
            ccount = ccount * 2

            if ccount = 16 then
                ccount = 1
            end if

        end if
        if leddir = 1 then 
            ccount = ccount / 2

            if ccount = 0 then
                ccount = 8
            end if

        end if

        wait ADCreading ms
goto main
sub Setir
    ;if SwitchIn1 = 0 then
        for tt = 1 to 2
         Set PortC = 9
        wait 250 ms
         Set PortC = 0
        wait 250 ms
         Set PortC = 6
        wait 250 ms
         Set PortC = 0
        wait 250 ms

        next

        if leddir = 0 then
            leddir = 1 
            ccount  = 8
        else
            leddir = 0 
            ccount = 1
        end if
    ;end if
    On Interrupt PORTABChange  Call Setir

end sub

How do I raise the event ?

Thank you.

[Anobium]

So, I have figured out.. that RA2 is the only External Interrupt and I can use 'ExtInt0' to call the handler.

On Interrupt ExtInt0  Call Setir

How do I set up  an interrupt using any PORTA pin using the an interrupt-on-change (IOC) option? I want to use RA3.

[kent_twt4]

1)  There is an extra PORTABChange in the Setir sub that is not needed.

2)  While everything is set up for the PORTABChange, you still need to say which pin(s) will be used.  By default the SFR IOCA register bits are '-00 0000' on BOR, POR (see pg. 33 of data sheet).  So "Set IOCA3 On" should do it prior to main.  The demo board already has a 10k pullup, so good to go.

[Nobody/Anonymous]

Works a treat!  thank you.

I need to get used to mapping  the datasheet to the GCB dialog and syntax.

Thank you.

[Anobium]

The working code is shown below.  This is not optimised but it works…

#chip 16F690, 4
#config Osc = XT, MCLRE_ON
'Set the input pin direction
    #define SwitchIn1 PORTa.3
    Dir SwitchIn1 In
#define LedPort PORTc
    DIR PORTC OUT
'Setup the ADC  pin direction
    Dir PORTA.0 In
    dim ADCreading as word
'Setup the input pin direction
    #define IntPortA PORTA.1
    Dir IntPortA In
    #define intstate as byte
    intstate = 0
    #define minwait 1
    dim ccount as byte
    dim leddir as byte
    dim pushcount as byte
    dim madestart as byte

    ccount = 8
    leddir = 0
    pushcount = 0

'Setup the intertupt - see page 33 of the 16F690 datasheet
    Set IOCA1 on
    On Interrupt PORTABCHANGE Call Setir

    initx:
        ' setup start values 
        if leddir = 0 then
            leddir = 1 
            ccount  = 8
            goto main
        end if

        if leddir = 1 then
            leddir = 0 
            ccount = 1
            goto main
        end if

    main:

                IntOn

                ADCreading = ReadAD10(AN0)
                if ADCreading < minwait then ADCreading = minwait

                Set PortC = ccount
                wait ADCreading ms
                intstate = 0

            if leddir = 0 then 
                ccount = ccount * 2

                if ccount = 16 then
                    ccount = 1
                end if
            end if

            if leddir = 1 then 
                ccount = ccount / 2

                if ccount = 0 then
                    ccount = 8
                end if

            end if

    goto main

    sub Setir
        if IntPortA  = 0 and intstate = 0 then 
            intstate = 1
            goto initx
        end if
    end sub