Just a note that I have some new boards in stock now, I’ve also renamed it into "“Doorbell modernizr” 
Because soldering was taking a bit too much of my time and was too error prone, I now got some professionally assembled. This doesn’t however make it cheaper unfortunately (you would need to go to pretty high batch sizes for that).
All code and designs are still open source:
The device now also works with Domoticz and OpenHAB out of the box by the way 
Just to echo my post above, a big 
to @ErikNL Have had one of his doorbells for the last 4 months, and it’s perfect. Integrated straight in HA, super easy to setup. If you are looking to make your dumb doorbell smart, this is definitely the way to go.
HI, i am also verry interested in this doorbell, at the moment i have this system in house
https://entrya.eu/wp-content/uploads/2017/10/Facila-DP132C-NL.pdf
if i buy that system from ericnl do i just need to attach the wire like in the picture below? doest it mather where i put the + and - ?
also, the outpost has a camera, is it possible to capture the camera stream somehow of those 2 wires?
thnx in advance
This project looks great! I’ve been looking to add something to the hardwired doorbell and keep it simple. The only thing I can suggest is maybe using the AC transformer to power the unit instead of another wall wart.
The transformers are always in a hidden spot under a floor joist, in a crawl space under stairs or some weird spot. Usually a receptacle is not near and just having a 7-24VAC converter along with the 5v plug would make it universal and easy to use.
Agreed. If it used AC power from the doorbell transformer, that would make this perfect.
My two cents on powering a sensor for a traditional doorbell:
If neither the doorbell transformer nor any other wired power source is easily accessible I would recommend to use @tlsGoud 's solution but with a battery-powered wemos d1 mini and the following modifications (to make the batteries last for at least some months):
For the people who wonder whether the ESP node could be powered with the doorbell AC transformer current of a button press because the transformer itself is not accessible: With a supercap it could work but probably not reliably.
Reddit’s markus_b did some math here: https://www.reddit.com/r/esp8266/comments/4slt3a/sanity_check_for_doorbell_project/d5b69uh/
An alternative for this would be to add a 433mhz transmitter to your traditional doorbell as it needs a lot less power than a wifi module and thus could be powered with capacitors. Here is a project where someone built that and documented it quite well: http://www.maltepoeggel.de/?site=klingelerweiterung
Of course you’d also need a 433mhz receiver for HA then if you haven’t already.
Okay guys I wanted to have my own smart doorbell to add to my home automation setup. I lke the idea that was shared by armand janssen. I orderd all the items and they are send so I hope to receive them soon.
Anyways currently my setup is like this:
So based on the wiring image shared by armand i was just drawing my idea into a wiring image:
But as you can see I dont believe this will work or maybe even kill my esp and relais setup.
anyone who can help me out 
For me i used a cheap 433MHz wireless doorbell which is also read by the equally cheap sonof rf bridge, which then relays an mqtt to HA.
Ok I made some better diagrams. Still not able to get it to work.
hereby my current situation:
So I tried to insert my wemos d1 + relay in between. but no effect.
If I press the button I dont hear the bell
Shoul I connect the power from the fuse box to the COM or NO port?
I have update my last input somebody who can help me? It is wired as shown but no sound currently. 
Your schema looks ok. I don’t understand your doorbell in the drawing, but looks good.
Do you hear the physical click from the relay?
Did you configure the correct port?
I dont hear anything as far as I have tested.
I have connected the doorbell wire to D2 and the other one to GND.
As mentioned in the code.
this a photo of my doorbell gong and the wiring.
Did you put the relay correctly on the wemos ? Soldered it?
Try with a simple buzzer or led instead of your doorbell.
This to test the relay. It should give a click sound like in https://youtu.be/zup17vYASlU
This is great and I feel like if I was smarter I wouldn’t need a follow up question but…
on my ubuntu pc thats running Hass.io in docker I have setup moquitto. Basic install expect a different port.
Its running lights and my doorbell. The lights are fine but for the doorbell automation I use a MQTT trigger.
That one has the same issue has christian.ek mentioned.
When I try to run the moquitto_pub command I get an error " Error: Connection refused"
Its definately user error but is there anyway you can help clarify running the _pub command? I tried stopping the MQTT service and running _pub -t HA -r -n but got the same error.
I think hassio sets up a required username and password for mosquitto, so you nee
mosquitto_pub -t your_topic -r -n -u username -P password
I think the password parameter is a capital p, but I don’t use them myself so I may be remembering incorrectly.
So I bought the DB Modernizr from @ErikNL in the interest of just getting it hooked up and done with. Unfortunately I am getting constant triggers.
I have a 24v transformer wired to a LaView PDB1520F1 video doorbell, which is then wired to my chime. I have not traced all the wires as they all change colors a gauge, but I am getting a constant 2.2v at the chime terminals. Erik’s DB Modernizr is wired in parallel at the chime. I created pigtails from the chime terminals and wired in the leads from the doorbell and pigtails from the DB modernizr. Is the constant 2.2v what is causing the constant triggers? I do not know yet what the change in voltage is when the door bell is pressed as my assistant (my better half) is out of town at the moment. Do I have to add resistors in series with the leads to the DB Modernizr?
Since the4 Modernizr works roughly the same as my bell, I would expect 0 voltage when nog pressed and 5v when pressed (when connected to ground and a pin on the Arduino). So the pin goes from “down” to “up”.
try 1001 
i have found a wiring diagram.
Its a two chime doorbell. Have an ESP wemo D1 mini and relay.
I have tested the relay and it works. (seperate code) the main issue is the wiring with the ESP in between.
If this does not work I will consider taking away the bell and just have some sound send to my bluetooth speaker instead of. But the is a worst case scenario.
THANKS
Please I need to make this work
I have the same issue.
before with my stupid doorbell everything worked fine.
Now with my smart doorbell it’s giving continous triggers.
Did you fix it?
