Rather than installing stand alone motion sensors and using them to turn lights ON/OFF and to trigger an alarm system (that’s two “smart” devices: the sensor and the light swith or controller), it feels like using a motion sensitive light switch (one device, e.g. a Lutron Maestro Motion Sensor Light Switch) should also be usable to trigger an alarm system. However I have not been able to find a motion sensitive light switch that can be used that way (with either a wifi trigger, or a simple circuit closure wire like a plunger door contact). Thoughts?
You dont want that. Motion detectors for lights will be made to always detect movement and maybe go off too much since not detecting you is more annoying that 1 false detection.
Alarm motion detectors will only go off if they are pretty sure they see movement (that also makes them lousy for lights, since they will trigger much later).
Alarm wise you will want a separate system preferably wired.
Thanks, thats a great point, had not thought of that. Still, if it’s a question of how to filter, average, or change the threshold for triggering, this would be a cool feature for one of the motion switch vendors to add (and I am less worried about network connectivity with matter/thread although hard wired always better). I like the idea of using a single device that sits in an outlet box, rather than two seperate devices with seperate wiring.