how to read ky40 mechanical encoder ?

[iw2fvo]

Good day to all of you in this forum.
I used an optical encoder in the past with pbp and I had good result.
Now I have a mechanical encoder similar to the ky40 or ky-040 that is widely available on the net.
I am not able to make it working correctly and still having bad results.
I did filtered the A and B signals with two 0.1uf and 10k resistors pull_up: no solution up to now.
Any help on the this matter please ? Or any sample code available ?
Thanks
Ambrogio

[Archangel]

Is your encoder like this ?
http://www.ebay.com/itm/400964660325...%3AMEBIDX%3AIT

These encoders are (supposedly) destroyed by pullup resistors.

Or is your encoder just a noisey old mechanical switch type?
Comparators are supposed to be good buffers for mech switches.

OK I found my answer, Mech. as stated in your post
You are needing to "debounce" these.

[iw2fvo]

this is my ecoder:
http://www.ebay.com/itm/1PCS-KY-040-...item27e8f12b89

Any help , please ?
Thanks
Ambrogio

[Archangel]

CAUTION: UNTESTED CODE

main:

A var portb.6
B var portb.7
state var byte
if(( A == 1)&&(B==1)) then state = 1
if(( A == 1)&&(B==0)) then state = 2
if(( A == 0)&&(B==1)) then state = 3
if(( A == 0)&&(B==0)) then state = 4
;pause 100
if state = 1 then portC = %00000001
if state = 2 then portc = %00000010
if state = 3 then portc = %00000100
if state = 4 then portc = %00001000

debug "  state = ",#state


goto main

[richard]

I found this interesting.
http://makeatronics.blogspot.it/2013...ture-with.html

is your "re " a 20 count per turn with indents ? the 10 for a $1 ones I got from ebay have enough contact bounce to start a spring factory but the inherent software filtering of the above code does an amazing job on them 1 (4k7 pu r's and .1uFs included). I have not ported this to pbp but have for mikro c and xc8 if that helps

http://www.circuitsathome.com/mcu/re...age-1#comments
this link has some other insights

basically you just need to adjust your re count using this current value / old value matrix (illegal values [bounces] are just ignored )

[pedja089]

One of possible ways to implement filter(Not tested)

OutputValue=0
Select Case OldValue
Case 0
If Current=1 then OutputValue=-1
If Current=2 then OutputValue=1
Case 1
If Current=3 then OutputValue=-1
If Current=0 then OutputValue=1
Case 2
If Current=0 then OutputValue=-1
If Current=3 then OutputValue=1
Case 3
If Current=2 then OutputValue=-1
If Current=1 then OutputValue=1
EndSelect

[iw2fvo]

still not able to make my panel encoder working .
Could someone post the complete code applicable to mechanical encoder like my one please ?
Thanks in advance.
regards,
Ambro