[chbot] Fixing bouncing rotary encoder

[Mark Atherton]

See if you can take the encoder out and inspect it.

If it's optical, it may be a fluff-problem, or dirty pickup optics; a 
good clean may help,

If its a mechanical encoder, again, disassemble and clean it, it could 
still be a fluff-problem. A squirt of contact cleaner may also be beneficial

-mark


On 6/11/2016 5:57 PM, 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)?
>
> Set the capacitor so that the RxC = about 1/10 of the period of the 
> nominal "clean" frequency you want.
>
> Alternatively, if you have a scope handy and can see the glitches, set 
> the value to about 5 x the period of the glitches.
>
> That should give you a reasonable starting point.
>
>
> Rotary encoders should be doing quadrature encoding. I've seen that 
> messed up in firmware at least 50% of the time.
>
> On Sun, Nov 6, 2016 at 5:44 PM, Volker Kuhlmann 
> <list0570 at paradise.net.nz <mailto:list0570 at paradise.net.nz>> wrote:
>
>     I have a digital power supply that has developed a bounce problem with
>     its twiddle knob, making it pretty much unusable. Someone at the last
>     meeting mentioned the quick fix is to put in a capacitor, but I don't
>     remember the details. Is the capacitor across the contacts? And what
>     value? 100pF? 100nF? Wouldn't burn 100nF the contacts out?
>
>     Obviously this tool has s... firmware, but I can't fix that. Plan B is
>     to try and replace the encoder, but if a quick fix works that'll save
>     some headaches with models, sizes, etc.
>
>     Thanks muchly,
>
>     Volker
>

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