Notify HASS when doorbell rings (URMET electronic type), with ESP8266

Hi, I have the below doorbell. When outside the button is pressed it rings in the phone body. From the instruction manual I see that
6 and 9 is the door opening (I attached the 2 black wires to an ESP8266 with a relay and works perfectly
1 and 2 should be the speaker and microphone
CA should be the doorbell ring.

My question is how to use the CA with an ESP8266, simply connect it to a GPIO, or do I need some sort of circuit (resistors or something),? Sorry I know very little about electrronics.


Hi @Klagio, I have the same doorbell and I would like to somehow connect it to ESP8266 aswell and I found your post. Do you have some update on this very old topic? Did you find out how to connect the CA cable? Thanks

no I was not able

Hi, I think it’s the same of my intercom.
You can take a look to my project below.

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Hi @ilfuriano, thank you for sharing yout project, it looks like exactly what I’m looking for.
Could you please explain the exact function of LM2596HV converter and PC817 optocoupler in your project? I have only a very basic knowledge of electronics and I would very much like to know what exactly is going on here and how it works.
It would also be great if you can add some photos of your setup into your repository, I would appreciate it very much and find it very helpful.

Hi @Marhub,
this is my first project and I build it with my beginner knowledge.
The LM2596HV converts AC (intercom) to DC signal at predefined value. In that way the esp can read it as digital input. The optocoupler separates the controller (ESP8266) from the intercom becouse they are two differents circuit with different power.

Does anyone make this idea (@ilfuriano’s) working?