Making a COCO doorbell compatible with Shelly

Hardware
1

Hi All,

Just got started with home assistant, moving away from Homey. Without going into much detail, my Homey 8 years old, and I don’t know how much life is in it anymore. As I have recently built a small k8s (containers) cluster for all my home server needs, I figured I might as well move to home assistant and gradually phase out Homey. This means I’m running HA core and I prefer to keep all communication IP based (so no USB dongles). In cases where I cannot make due with IP, I will opt for a network based bridge (e.g. my Somfy blinds, Philips Hue)

For one specific integration, I am looking for a simple and cheap solution. This is for my doorbell. With Homey I had it automated using a Click On Click Off solution that integrated directly with Homey. It looks like this (current). (I had to combine the images into 1 file, as I am a new user)

Since I don’t have a bridge for 433/COCO, I was thinking about doing something with an ESP32, but later thought maybe a Shelly is even easier. I don’t have any experience with Shelly though and am looking for advise whether it is possible to accomplish what I’m trying to achieve.

I was thinking about “injecting” a Shelly relay between my doorbell and the transmitter (idea).

As this isn’t a powered circuit, but simply a push contact, I figure I need external power (e.g. a 12v adapter). The Shelly would need to shortly activate the relay to upon pressing the doorbell to activate the transmitter, so the receiver rings. It would also have to send out some sort of signal to HA so I can trigger automations.

I was wondering if I even need to put the transmitter behind a relay. Considering it is a “push” contact, I figured, maybe it could even be connected in parallel with the doorbell (parallel)

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I hope the community can advise me on whether this would work!

2

While total overkill, your Shelly circuit through relay is correct and waterproof way of getting trigger. Shelly Plus 1.
Another benefit, you can mute your doorbell (and prank other people in house).

Any other way you need to study little bit your doorbell circuit. You can’t just connect button in parallel with shelly without knowing what level button is switching in doorbell. In that case other options would be Esphome devboard on button or on receiver or RF receiver to catch the signal.

3

All you would need when its connected is to make sure that the switch input is set as a momentary switch for it to register properly when pressed.

The other option is to get a CT clamp and have it read the current change when the button is pressed and run the automation when its at or above the detection threshold.

4

Thanks for the responses. I have implemented it in the relay way. I have set the Shelly to button mode as a momentary switch. It works great. I have added it to Home assistant and can detect the on state in node red, which I use to send a message to my phone.

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