Actually in re-reading this, I see what you were asking. No, if the resistance is there, it will continue to raise/lower the volume. E.g. if I just put a 16k or 24k resistor across the stereo pins, it will raise/lower the volume until I remove the resistor.

Okay, then it needs to be a pulse.

 

Hi @crutschow I have my parts and have attempted to get this put together but haven't gotten it to work yet. I may be a little confused on the rotary encoder part. Are the X and Y corresponding to my A and B, then I put the middle pin to Vdd? Also just curious how important it is that C1 and C2 are directional? I don't have any electrolytic 0.1uF so I subbed in more of the C3 and C4 in their place. Last I'm not 100% sure on the output, that should be going straight to my 3.5mm tip, then Vdd to my sleeve? Or is there a 20k resistor across there too? I am not super familiar w/the simulation outputs and stuff. Thanks for the help!

 

Are the X and Y corresponding to my A and B, then I put the middle pin to Vdd?

Not sure.
Most likely the middle pin goes to ground with 10kΩ pull-up resistors from each output to 12V.
Post the data sheet for the encoder you are using.

how important it is that C1 and C2 are directional?

That's only if the capacitors are polarized (electrolytic).

I'm not 100% sure on the output, that should be going straight to my 3.5mm tip, then Vdd to my sleeve?

My understanding that you want the resistor to go to ground, so you need ground and Vdd to my circuit, and the signal going to where-ever the signal needs to go, which requires a three contact connector to my circuit.

I would suspect the tip would be the signal, and the sleeve is ground.

 

Is the 13V input just to be easier to match the car or selected for another reason?

Selected to match the car voltage which varies around 13V to above 14V when the engine is running.
My circuit will tolerate that.
But add a 100uF, capacitor from the V+ to ground to filter the car voltage.

 

Not sure.
Most likely the middle pin goes to ground with 10kΩ pull-up resistors from each output to 12V.
Post the data sheet for the encoder you are using.

Ahh that may be part of my problem then. I'm not sure I have that wired correctly. Datasheet attached. I _think_ it is the EC111.

That's only if the capacitors are polarized (electrolytic).

Right, I meant to say, is it ok for me to swap in a non-polarized one since the schematic calls for a polarized one. I have extra mylar 0.1uFs available for C1 and C2 but wasn't sure if that was an ok swap.

On the output, the super ridiculously simple test works. If I wire up just a 24k resistor from tip to sleeve on the 3.5mm connector, it definitely turns the volume up and keeps doing so until I remove the resistor.

Thanks again for all this help! I am learning a lot in the process here too.

 

that may be part of my problem then. I'm not sure I have that wired correctly.

Look on page 167 of the data sheet.
That's how I described the required connection (resistors are nominally 10kΩ).

 

Awesome will give that a shot. In arduino land I had just wired them directly to the inputs so this is new to me haha.

 

In arduino land I had just wired them directly to the inputs

Even in Arduino land, you would need to connect it the same way.

 

Even in Arduino land, you would need to connect it the same way.

I think in Arduino land, you can just activate the internal pull-ups on the two inputs in code, so you don't need external resistors.

 

I think in Arduino land, you can just activate the internal pull-ups on the two inputs in code, so you don't need external resistors.

Okay, good to know.