Rotary encoders?

[pierrepierrepierre]

I want to try something out with a couple of “infinite” knobs.

I believe the best option would be rotary encoders. I’ve never done anything with encoders before. I’m ready to place a Mouser order for other stuff just now, and I’d like to add encoders onto it, but I can’t figure out which encoders to get.

I need them to be multi-turns, infinite, and also have a toggle button when I press them. I’m not quite sure yet but I think I need the incremental type. And obviously, cheapest is best at this stage.

Could somebody advise?

 

[jan.didden]

Depends on the software you want to use with the encoder. Most encoders have two outputs that are 90deg out of phase, so the software can detect direction of rotation by looking at those two outputs. They have no end stops so the limit/min/max needs to be implemented in the software.
The button is generally implemented as a push-button on the shaft.

So before deciding which type of encoder to get, think about how you want to implement the application.

Jan

 

[pierrepierrepierre]

Depends on the software you want to use with the encoder. Most encoders have two outputs that are 90deg out of phase, so the software can detect direction of rotation by looking at those two outputs.

I’m writing the software myself. What you describe is exactly the physical behaviour that I need.

The button is generally implemented as a push-button on the shaft.

That’s also what I’m looking for.

 

[jan.didden]

In my experience, the best 'feel' you get with 15-24 PPR (pulses per rotation) incremental encoder.
But you need some smart software to catch situations where people are turning the encoder so fast that the software misses a pulse and erroneously thinks that it rotates in the other direction. I build it such that in such cases it just skips processing until the user slows down. He/she always does when he/she notices that nothing happens. But you might have other/better ideas.

I think I used something like this: EC12E2430404 ALPS | Mouser Belgique

Jan

 

[Enzo]

There are a couple kinds of encoders. One type is the absolute, which tells the system which point the knob faces. In other words each stop means a specific thing. This is not what you want. The other is simple increments, typically as Jan described: two outputs in quadrature. SO three legs, one common and the other are the two outputs. They simply pulse opposite one another in time. In other words turning down side A closes first, then B, while turning up side B closes first, then A. SO in practice, the system watches one of the inputs as the counter, and the other as the direction. So side A can be my counter. Each click pulses me down one. I watch side B. If it closes first, then my count is applied the other direction.

 

[pierrepierrepierre]

Thanks for the further the part suggestion, and the logic description — it’s helpful