Encoder Filter recomended

[novski]

Hi

I tested a encoder filter that is recommended by the manufacturer and it works. but im not so sure about the consequences.

I will ad a schematical drawing to show what i mean.

The question is: can i use this schematic without troubles?

Thanks a lot

Novski

Edited February 6, 2015 by novski

[mono]

hi novski,

 

short answer: YES! personally i cant see the point of having r5 & r6 in the circuit. this will only half the values of r3&r4 (?). 10k for r3&r4 (pullup) is alright anyway. for the filter itself i would decrease the c1&c2 values to 10nF. the encoder impulses are very short and i dont think that you get decent results with 100nF.

 

btw. im always connecting encoders with this additional filter. this way i can use the cheapest encoder and still get good results, even if the cpu is slow...:-)

 

regards,

mOnO

[FantomXR]

But they aren't necessary, are they?

I used a lot of Bourns PEC16 Enc and never had trouble with those without the filter.

[Marxon]

What does Thorsten say about it?

Because MIOS allready has a software debouncing function.

[mono]

...as i said, you need the filter, when using a "slow" cpu. with slow i wasnt refering to the stm32 or the lpc17, that mios32 runs on. both are anything else than slow! it was rather a general question about encoders and a general answer. try connecting different encoder-types with a small 8-bit pic or atmel and you will see, what happens with and without the filter. :-)

 

regards,

mOnO