Make a dumb doorbell smart with Shelly 1

The fact that you have to wait 5 seconds for any window/door contact does not sound right. What are the make/model of the door sensors you have tried?
Anyways, I have z-wave, and (at least in my case) my tests with my Ecolink door sensor is both consistent and immediate.

Ref: Contact Sensor for Doorbell - #15 by Bartem

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on the other hand, what you really need, conceptually, is a sensor that can tell you whenever the sensor sees 230VAC betwen L and N. So kind like a “power outage sensor”, but in reverse logic.
And to be clear, you do not need “power monitoring sensor” that tells you Voltage/Amp/Watt, etc., but just a “power outage” that tells you whether 230VAC being on or off. I have not seen any off-the-shelf sensor devices that you can buy and it would just work, so most if not all of the examples are DIY, and I can tell you wouldn’t mind DIY:

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Do you have any link to the manual of the Schneider brand doorbell?
I am curious because is that really 230VAC both at the bell location and (gasp!) at the doorbell button location, that is outdoor and for people to press daily…? Is there a way to use multimeter to test the button outdoor, and see whether the bell button is indeed switching 230VAC…?
I mean, if so, I’d be interested to see how Schneider addresses safety concerns.