On Thursday, 16 March 2017 09:17:43 GMT Ralph Corderoy wrote:
> Good. I don't understand the electronic side enough to judge if the
> capacitor circuit he gives is sufficient for this purpose. Give me
> bits! :-)
Looking at what I've got and what the RC circuit should really be, I'm coming
to the conclusion that my circuit debounces the switch when it is released and
not when it is depressed.
However, that doesn't quite stack up with the behaviour I've seen. I'm still
analysing that.
> > I was trying to avoid that and my single cap and pull-down resistors
> > technique seemed to work until this cropped up.
> The GPIO's software debounce logic is poor and removing the bouncetime
> argument gets it out the way. It seems there could be finer grade
> debouncing already happening lower down the software/hardware stack and
> that may be sufficient. If no bounce ever reaches the Python then the
> GPIO library can just call your handler on both 1 and 0 and you can keep
> a tally of which it must be and only act on the 1s. Ensuring no bounce
> makes it through might already be happening without you modifying your
> existing circuit. Perhaps now you know why ganssle.com suggest the
> change you can try and recreate that circumstance?
I think there is some bounce because when I increased the value of bouncetime
it pretty much disappeared (until this).
I've just got in from running errands, so I'll report back when I have a bit
more of an understanding of what is going on.
--
Terry Coles
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