For example, a button that seems visibly pressed (even lights up! Maybe there's even audio or haptic feedback!) but once you release, nothing actually happens because you were supposed to press it or hold it down for slightly longer.

This even happens with physical controls: in some elevators you can press a floor button such that it lights up momentarily, and even beeps, and yet the elevator doesn't register the command and you have to press again, longer.

[–] xthexder@l.sw0.com 5 points 3 weeks ago

I've actually noticed this exact thing with elevators before... I was kind of amazed the beep and light were hooked up completely independently from the actual floor selection logic.
It sort of makes sense that the light in the button would just be hooked directly up to the button contacts. The computer would then be polling the buttons separately and it's possible to miss a button press... These sorts of buttons shouldn't need a debounce period since pressing any of them a second time doesn't do anything. If the buttons were interrupt based, this probably wouldn't happen.

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