Quad Decoder for ABI Signals will not work

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MaWo_1214996
Level 3
Level 3
First like given

Hello,

I have problems, getting the Quadrature encoder to work on the PSoC 5lp.

Using the 050 Kit, I can get only random numbers on the display. Sometimes it updates, sometimes not. It does not behave as I expect it.

I want actually only to display the counting values on the display in decimal form. Count up and down to the Maxima of the encoder, and then reset with the index pulse.

Attached is my minimal design.

If someone please can have a look and pint me in the right direction?

Thanks in advance...

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1 Solution

The one rotary encoder I have is for 5V, but works down to about 3.1V, I have tested it and measured also the signals with an oscilloscope when they are connected to the pins.

I found the problem now and it works:

The Quad Decoder Component expect a logic low index pulse, my encoders have a logic 1 index pulse. By adding a NOT Gate to the index pulse it works fine now.

I found this by trying to not use the index pulse and then it counts correct.

If someone experience a similar problem with encoders: So please check the polarity of your signals always.

View solution in original post

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2 Replies
JOLO_264146
Level 4
Level 4
First like received Welcome!

Hi,

have you seen if you have signal in the rotary encoder? I ask because I had similar problem with other kind of rotary encoders with extended power supply (PS) and at the end the problem was the min PS was 5.5 (not 5V), I had 6 encoders with different behaviors, With a PS of 6V, running without problem.

0 Likes

The one rotary encoder I have is for 5V, but works down to about 3.1V, I have tested it and measured also the signals with an oscilloscope when they are connected to the pins.

I found the problem now and it works:

The Quad Decoder Component expect a logic low index pulse, my encoders have a logic 1 index pulse. By adding a NOT Gate to the index pulse it works fine now.

I found this by trying to not use the index pulse and then it counts correct.

If someone experience a similar problem with encoders: So please check the polarity of your signals always.

0 Likes