Hello,
I wanted to create a project that uses what I would call a pulse encoder or optical encoder. But I cannot for the life of me figure out the correct keywords. I keep getting the type used to measure RPM or some such thing when searching on ebay.

What I expect to do is to turn the knob in circles as many times as I want and as it spins it sends pulses to my microcontroller. I've seen and used these things, like on an oscilloscope.

Thanks!

 

rotary encoder

 

Or shaft encoder.

 

And they are basically the same thing that is often used to measure RPM.

You need to determine how much resolution you want, which will dictate the minimum number of pulses per revolution that you can live with.

If you need finder resolution than a reasonably-priced encoder can deliver, one option is to gear your knob to an encoder shaft so that each rotation of the knob produces several rotations of the encoder. You can buy (or at least used to be able to) setups like this off-the-shelf.

 

any quadrature encoder will do.

if this is meant to be used by hand, you will want low resolution one, with detents. you can find them on Amazon or Mouser, Digikey etc.

https://www.handsontec.com/dataspecs/module/Rotary Encoder.pdf

 

Hi ball,
This blog link is MCU option as a generator.
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https://forum.allaboutcircuits.com/...signal-gen-2-phase-non-overlapping-clock.654/

 

any quadrature encoder will do.

if this is meant to be used by hand, you will want low resolution one, with detents. you can find them on Amazon or Mouser, Digikey etc.

Not necessarily. While a low resolution encoder with detents would be well suited to some applications, such as it having the feel and behavior of a selector switch, it would likely not be what you would want for other applications, such as a game control or anything where you wanted the feel of a smooth, continuous control.

As always, it comes down to what the problem actually is, which we don't know enough about.

 

that is true and we can only go my what was stated. i proposed that product type because he did mention "like on an oscilloscope" sounds like manual input to adjust settings.

 

that is true and we can only go my what was stated. i proposed that product type because he did mention "like on an oscilloscope" sounds like manual input to adjust settings.

Perhaps. But even on a scope you have both discrete setting knobs and knobs that you want a more continuous feel, such as trigger level, cursor control, trace offset, ...

Hopefully the TS will provide more information about what they are actually trying to accomplish.

 

That is true and we can only go by what was stated. I proposed that product type because he did mention "like on an oscilloscope" sounds like manual input to adjust settings.

You understood correctly. A low-res encoder is what I sought.
Thanks to everyone's help, I've found what I was looking for.

 

It will indeed be a lower resolution quadrature encoder. We did that on a test stand 30years ago because we anticipated problems with analog inputs and variable pot. It was beautiful, and because we used a ball bearing encoder it lasted for many years. The user would push a button to select which parameter they wanted to adjust, and then turn the knob. And with continuous rotation there was no stop that they could break.

 

Typically called a Pulse Wheel Generator, used on CNC machines to manually position axis, the resolution is mainly 100p/rev.
Consists of a quadrature pulse generator.

https://www.prisk.org/product-p-752371.html

 

O think that on our machine it was called "ADJUSTMENT", because it changed different variables depending on which button was pushed. It was a testing machine and the year was 1986.

 

Currently being advertised by WalMart of all places??!!

 

Not to argue, but I find it really difficult to believe WALMART is actually trying to sell it. I can imagine a fraud faking Walmart.

 

You would be suprised what Walmart is selling now,! often order in.
Remember, they are China Based!!