[chbot] Fixing bouncing rotary encoder

Volker Kuhlmann list0570 at paradise.net.nz
Sun Nov 6 06:18:19 GMT 2016


On Sun 06 Nov 2016 17:57:26 NZDT +1300, Charles Manning wrote:

> A capacitor across the contacts might help.
> 
> What is the value of the pull up resistor? How often do you expect to see
> pulses (if it was clean)?

Thanks Charles! No DSO handy so I'm not sure. Your dimesnioning
guidelines look sound though. I couldn't find the pull-ups, traces
disappear underneath CPU without being connected to a CPU pin, or
anything else I touched with the meter. And there were caps across the
contacts already. Nothing to loose, so I added 100nF each and it works
again. For now anyway, longer-term I might have to replace the encoder.
A bit dubious circuit though. Like you, Jack Ganssle and lots of others
say, most switch debouncing is rubbish.

Cheers,

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.



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