Still having trouble with rotary encoder volume control

Hi,

Dave, I followed your suggestion and looked at your post from a while ago, https://ez.analog.com/dsp/sigmadsp/f/q-a/120659/adau-1701-rotary-encoder.

I'm using a Bourns series PEC11R rotary encoder — https://www.bourns.com/docs/Product-Datasheets/PEC11R.pdf. From what I can see, on the figure Quadrature Output Table on the first page,

and Suggested Filter Circuit on second page, it seems like this encoder is a "Type 1" (using the informal terminology you proposed in your post), which you say is the behaviour that the SigmaStudio rotary volume control expects. I am using the suggested filter circuit, and connecting to M12 and M13 of the ADAU1466 using the evaluation board:

I did confirm with an oscilloscope that the waveforms are consistent with the Quadrature Output Table figure in the datasheet. Does the rotary volume control imposes any timing requirements on the pulses? That was the only "weird" detail I could notice — when moving a single click, I would see the two pulses, with overlap as expected, but some times one pulse could be something like 10 or 20 times longer than the other one (for example, maybe signal A goes to 0 at t = 0, then signal B goes to 0 at t = 20 ms, signal A returns to 1 at t = 20.5 ms, and signal B returns to 1 at t = 21 ms, or strange timings like that)

Notice that I do get audio if I set a value ≠ 0 as the first entry of the table (the volume control seems to be set at the first table entry upon start, and since the control never reacts to the rotary device, the actual volume never changes).

Any ideas?

Thanks,
Carlos
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Audio Signal Processors

rotary encoder

sigmastudio

SigmaDSP Audio Processors

evaluation_board

adau1466

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