AVR-Chat

It can't fire if it is grounded.  If it IS firing then one of your
assumptions is incorrect:

A- You are actually attached to ground
B- That INT0 is actually what is firing

  So, disable the interrupt and see if the problem goes away - If it does
then assumption A needs to be examined.  If it does not then clearly
assumption B needs to be examined.

DLC

> Hi Zack,
>
> I've grounded it after not being able to figure out why it keeps
> firing.  I figured that if it was grounded it couldn't be a hardware
> issue.  I grounded it via a very short wire.
>
> Thanks,
>
> Richard
>
> --- In AVR-Chat@yahoogroups.com, Zack Widup <w9sz@...> wrote:
>>
>>
>> Hi Richard,
>>
>> My first thought is that if it's grounded, why are you setting it up
> for
>> use in firmware? Why not just disable it?
>>
>> How is it grounded?  Do you have a long circuit trace or wire to ground
>> that might be picking up crosstalk from other nearby lines? Is it
>> "grounded" through another circuit such as a TTL or CMOS chip?
>>
>> Zack
>>
>>
>> On Mon, 17 Dec 2007, Richard Cooke wrote:
>>
>> > Hi Folks,
>> >
>> > I'll try this question again as my post of Dec 15th didn't receive any
>> > replies.
>> >
>> > What would cause the INT0 to continually fire even if the pin was
>> > grounded?  I have the set to trigger on rising edge (MCUCR = 0x03) but
>> > it will keep triggering.  I have also tried to set it to "any logical
>> > change" (MCUCR = 0x01) but get the same results.
>> >
>> > Anybody have any ideas why a pin that is grounded would trigger an
>> > interrupt?
>> >
>> > Thanks,
>> >
>> > Richard Cooke
>> >
>>
>
>
>
>
>
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-- 
Dennis Clark
TTT Enterprises