Getting my doorbell as smart as possible

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Joined: 26 Apr 2019 16:11

Getting my doorbell as smart as possible

Post by JayEnn »

Hi everybody!
I live in a rented apartment, so I cannot upgrade to a readymade doorbell system with camera, intercom and whatsoever.
Right now i have a very basic door bell - somebody presses the button downstairs, it rings. I can press the opener - the door opens. There is no intercom or anything similar.

Thinking about that I will have a baby in a few months, I want to make this smarter, using a z-uno.
i want to be able to
- switch on/off the buzzer
- get notifications from a lamp
- and on my smartphone /my wife's smartphone
- press a button on my phone to open the door

Maybe also have some control like "if door is opened switch off the lamp" - but that's optional and for later. - so a door sensor would be a next step.

the programming part I guess I can manage myself - just with the part of soldering and buying matching parts I still do have a few questions. Attached there is a rough sketch of how I want to solve it.
zuno doorbell.png
zuno doorbell.png (11.65 KiB) Viewed 2146 times
what actual voltage the transformator has I didn't measure yet - will be smith between 5 and 24 volts - still to find out.
So my questions:
for relays 1 and 3 in need to switch the voltage from the transformator - 1 should usually be closed (so in case of failure/power loss the usual buzzer still works), 3 should usually be open, so I don't press "door open" 24/7 at the same event.
relays 2 should switch the 3.3V of the z-uno, controlled by the doorbell.
Any suggestions what relays to buy? I'm located in Germany - if availability depends on that.

2nd: how do I prevent, that if I have the buzzer on, it get's much quieter because some of the power goes thru the relays 2? I thought of adding a 1kOhm resistor behind it - not sure that's gonna have the desired effect and will not influence how relays 2 works.

Also I'll be very happy for any improvements or other suggestions - it's basically my first project that will have a real use later and is not only to play around with on Arduino - I'm more experienced on the Pi...

Thanks a lot

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