External microwave motion sensor Goobay 96011 (motion detection behind glass)
as a very simple solution to reduce power consumption, I have used the external microwave motion sensor of Goobay/Wendtronic in my MagicMirror project (https://www.wentronic.de/en/lighting/installation-und-power-supply/sensors/8697/mikrowellen-bewegungsmelder, can be found easily by searching for goobay microwave motion sensor).
It is a device working independently from a Raspberry and can be used to simply switch on/off the monitor used, if there is some movement in front of the mirror. As it is using microwaves it can be placed behind the glass. The manufacturer specifies a range of 8m, but I am pretty sure it is less if put behind the glass (mine is located in a room with 2m distance to the mirror, so I cannot really tell the maximum distance).
The device is just connected to 220V and provides the power to a connected device, here for example a monitor. Reactivity, keep time and day/night sensitivity can be adjusted.
I am not related to the manufacturer or any vendor, I just wanted to share my experience and if you have questions I am happy to try to answer them.
@HerrB92 your mirror, is it a glass panel with film/foil or a real surface coated mirror?
@broberg I am using an 8mm Pilkington Mirropane Chrome Spy. I believe it is a surface coated mirror, but the product description is not entirely clear on that point (“special offline coating”, whatever this is).
@HerrB92 okey then it’s a proper mirror
It’s just that there is a metallic coating in most real mirrors which messes with many types of sensors. Glad to hear that the microwave sensor doesn’t care about that! It opens up the options when designing the mirror!
So wait how do you have the sensor powered and hooked up to the moniter?