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by layer8 491 days ago
Controls that require a feedback loop have more cognitive overhead than controls you can just use “blindly” (this includes not having to check for haptic feedback to test what mode it’s in) and from pure muscle memory. For example, you learn that your preferred volume when driving on a highway is at (say) the two o’clock position, and with time you’ll blindly turn the knob to that position without even consciously thinking about it. If, on the other hand, you “know” that the knob could be in a wrong mode, you’ll tend to hesitate when operating it because of that anticipation, having to check back whether the knob is indeed in the correct mode.
2 comments
Animats 491 days ago
Right. This "smart" knob is symmetrical, with no pointer that you can feel before turning the knob. So it's hard to use without looking. This is inferior to a simple mechanical knob.
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CRConrad 491 days ago
It's not infinitely rotatable, though, like some knobs are; TFA mentioned a 270° rotation range. So a pointer “beak” (or some other haptically recognisable asymmetry) should be easy to add.
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Animats 491 days ago
It's infinitely rotatable unless the software tells the motor to push back. The encoder appears to be relative, rather than absolute, so the physical positioning at power-up is unknown. Thus, the physical knob can't have a physical pointer with consistent behavior.

I have an LG washing machine with a knob like that. After power up, you have to turn it one notch before it lights up to indicate the current position, which is the default Normal cycle. So the knob has to be symmetrical, with no tactile pointer.

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CRConrad 490 days ago
> It's infinitely rotatable unless the software tells the motor to push back.

Aha? OK, I read that wrong then.

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ngcc_hk 490 days ago
The key is the blindly … driving is really a dangerous thing. Eye on as things happen.

I still have a nightmare about the dog of my relative run to the road and get out between 2 parking cars. It is a miracle it was not killed. I would not be able to detect it if I doing all these knob and feedback thing.

The old lady driving and stop in time in her old car … knobs and eye on help

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