Happy Chinese New Year!Elecrow will be on holiday from February 14–22 (GMT+8). You may still place orders of products and
manufacturing services as usual, and we will resume production and shipping by February 25.

user-img

SmartHome yourself
  • 12 Projects
  • 20 Followers
  • Jun 13,2025
+ Follow

Smart Doorbell Adapter – Module for Standard Wired Doorbells

Turn any wired doorbell into a smart Home Assistant trigger! This PCB uses a D1 Mini and optocoupler to detect the bell press directly from the existing transformer, no additional power needed. Fully isolated and ESPHome-ready—just wire it in and go.

Smart Doorbell Adapter – Module for Standard Wired Doorbells
 
  • thumbnail-img
  • thumbnail-img
  • thumbnail-img
 

Tools, APP Software Used etc.

  • EspHome

    fenxiang

  • Home Assistant

    Open Source
    fenxiang

Story

This PCB allows you to convert a standard wired doorbell into a smart device using a D1 Mini (ESP8266) and an optocoupler, without requiring any additional power supply. The built-in bridge rectifier enables operation directly from the doorbell transformer’s AC output (~8 VAC). Once the doorbell is pressed, the module detects the signal and can trigger automations in Home Assistant via ESPHome.

 

📌 Highlights:

✅ No extra power required – uses existing doorbell transformer
✅ Safe signal isolation via optocoupler
✅ D1 Mini (ESP8266) compatible with ESPHome
✅ Compatible with most wired doorbells
✅ Easy installation – just connect transformer and bell wires
✅ Includes schematic and ESPHome config
✅ PCB layout tailored for seamless integration

 

 

📌Full build guide and source files here:

👉 https://smarthomeyourself.de/standard-klingel-smart-machen

 

 

Video


https://youtu.be/RVVDfOkP3Do

 

Code

  • ESPHome Code

    https://smarthomeyourself.de/hc_downloads/klingel_esphome.txt
    View
Topic
View All
License: Attribution-NonCommercial-ShareAlike (CC BY-NC-SA)

Smart Doorbell Adapter – Module for Standard Wired Doorbells

Turn any wired doorbell into a smart Home Assistant trigger! This PCB uses a D1 Mini and optocoupler to detect the bell press directly from the existing transformer, no additional power needed. Fully isolated and ESPHome-ready—just wire it in and go.

9.8k
 
12
0
9
These revenues will go back into supporting creators, contests, and the open source ecosystem, and more.

Share your project on social media to expand its influence! Get more people to support it.

  • Comments( 0 )
  • Like( 12 )
/1000
Upload a photo:
You can only upload 1 files in total. Each file cannot exceed 2MB. Supports JPG, JPEG, GIF, PNG, BMP

You May Also Like

View All
Add to cart
Board Type : GerberFile :
Layer : Dimensions :
PCB Qty :
Different PCB Design
PCB Thickness : PCB Color :
Surface Finish : Castellated Hole :
Copper Weight : 1 oz Production Time :
Total: US $
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.

PCB Assembly

PCBA Qty: BomFile:
NO. OF UNIQUE PARTS: NO. of Components:
Country: Shipping Way:
Assembly Cost: US $
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
3dPrintingFile : Size :
Unit : Volumn :
3D Printing Qty : Material :
Total: US $12.99
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
Acrylic Type : AcrylicFile :
Dimensions: Engrave:
Acrylic Qty :
Acrylic Thickness:
Acrylic Color:
Total: US $12.99
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
CNC Milling File : Size:
Unit: Volumn:
CNC Milling Qty : Material:
Type of Aluminum: Surface Finish:
Tolerance:
Back to Upload File
Surface Roughness:
Total: US $12.99
As a sharing platform, our community will not bear responsibility for any issues with this design and parameters.
Add to cart
Item Price Qty Subtotal Delete
Total: US $0.00
Certified Product | Guaranteed Purchase: Full techsupport