Motion detector instead of switch?

With the appropriate components, it is possible to program whether the light on the guest locomotive automatically turns on after 02:37 or not. It is also possible to program that the light in the guest bathroom stays off if the light in the hallway is on. Or if it is darker outside than xxx, because then you can look inside. If the neighbor's outdoor lighting is on, he can't look inside...

Simply install a presence detector. As long as it detects occupancy, the light stays on. Add some delay time to that. We have sensors almost everywhere. I actually don’t need light switches…

Question regarding installation. If I want to install a motion sensor in the hallway on the upper floor, do I also need additional regular light switches? Or is the one motion sensor enough? I imagine that if you no longer want to use the motion sensor after x years for reason Y, it wouldn't work anymore if you only have the motion sensor or only one light switch. Unfavorable for a larger hallway.

How is it done in the hallway on the ground floor if you have an open living area? My concern is that the light turns on in the hallway every time you walk from the kitchen to the living room through the open area. The solution would actually be to orient it in the opposite direction so that the sensor does not cover the open living area. But there is no wall to install it on..

Why wouldn’t you want to use it anymore? Theoretically, [KNXfunk] would then also be possible. Detectors are available in all kinds of variants. Best to place them on the ceiling, not on the wall. There are detectors that cover multiple directions. Different sensitivities, brightness values, etc. can be set for each direction. Thus, easy separation of the rooms. You just have to use the right detectors, position them correctly, and configure them.

Maybe someone wants to walk through the hallway without activating all the lights?
How do I communicate this to the system?

For example, set only 10% light output by time or simply use the phone/voice… lock the detectors or set the scene.