RC filter on rotary encoder's terminal, should I use it?

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alexandros

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In the second page of this data sheet there's a suggested filter circuit with an RC filter on terminals A and B of the rotary encoder. I haven't seen many such examples in projects and fora when looking up rotary encoders, so I was wandering if it's really necessary. Also, the RC filters connect to 5V in the data sheet. In case it's good to have them, I guess Teensy's 3V3 will also be OK?

Thanks
 
Use whatever Vcc you have. Most people wouldn't bother and just use internal pullups - it that's unreliable there
might be some benefit from small caps. (Note the issue is not normally a problem with quadrature encoders
as they are inherently robust to contact bounce), its just that if both A and B are intermittent simultaneously due to friction
you could get unwanted counts than some low-pass filtering can prevent.
 
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