How to Turn Your Wired Doorbell Into a Smart Doorbell Using Home Assistant

Binary Tech Labs -

Are you looking to upgrade your home with a smart doorbell without spending hundreds of dollars on commercial options? With a few affordable components and Home Assistant, you can transform your wired doorbell into a smart one. No need to be an expert in electronics, and don’t worry—no soldering is required if you're not comfortable with it. Plus, this is a low-cost project you can complete relatively quickly!

In this guide, I’ll walk you through the entire process step-by-step, from gathering the hardware to setting up automations in Home Assistant. Ready to get started? Let’s dive in!

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Introduction

Most of us are already automating parts of our home, but one area that often gets overlooked is the doorbell. Converting your wired doorbell into a smart doorbell adds both convenience and functionality to your home. No need to replace the whole system; just a few added components can give you real-time notifications and remote access. This guide will walk you through how to set it up using a WeMos D1 Mini, some basic electronics, and Home Assistant for integration. This way, you keep your doorbell’s original function and add smart features on top.

Why Turn Your Doorbell Smart?

Core Benefits

There’s more to a smart doorbell than just alerts. Once set up, you’ll be able to integrate it into your broader home automation, trigger other devices, or even record logs of visitors. For anyone already running Home Assistant, it’s a straightforward and rewarding upgrade that doesn’t take much space or cash.

  • Stay Informed: Get notifications anytime someone rings the bell, no matter where you are.
  • Automation Ready: Connect your doorbell to other smart devices, like turning on outdoor lights or starting a camera recording.
  • Cost-Effective: You’ll keep your existing hardware and simply add some affordable components to give it a smart upgrade.

Basics of the Wiring

Most standard doorbells work on low-voltage AC. When the button is pressed, the circuit completes, allowing current to flow and triggering the chime. To integrate a WeMos D1 Mini into this circuit, we need a way to detect that signal without interfering with the original function. This is where an optocoupler comes in handy—it isolates the WeMos from the AC circuit, allowing us to detect the signal without risking a short circuit or interference.

Quick Note: In a nutshell, an optocoupler uses light to transfer the signal, which keeps both circuits (your original doorbell and the WeMos) electrically isolated from each other. It’s a simple but crucial addition to make sure the setup is safe and reliable.

What You’ll Need

To start, you'll need an existing wired doorbell, already installed at your front door. Then, Home Assistant will serve as the central hub to control this new smart device. For the brains of the setup, you'll use a WeMos D1 Mini, paired with either the WeMos D1 Mini Relay Shield or another relay of your choice to handle switching the doorbell. To power the WeMos D1 Mini, a 5V power source is necessary. While optional, a project box is recommended to keep everything tidy.

If you don’t mind waiting a little longer for shipping, you can find these parts cheaper on platforms like AliExpress or Alibaba.

Feel free to swap out components to fit your setup. For instance, in my testing, I used a different relay but opted for the relay shield in my home installation. You’ll find links to all the recommended hardware at the end of this article.

DIY Guide: Smart Doorbell Setup

Step 1: Flashing the WeMos D1 Mini

To make your WeMos D1 Mini “smart,” you’ll need to flash it with firmware using ESPHome. This is the software that will allow your doorbell to interact with Home Assistant.

Method 1: Flashing via ESPHome Add-On in Home Assistant‌‌

If you’ve installed the ESPHome add-on in Home Assistant, the process can be handled through the dashboard.

  1. Open the ESPHome Dashboard: Inside Home Assistant, navigate to the ESPHome dashboard and create a new device.
  2. Configure: Input your device details and WiFi credentials, or You can find an example configuration in my GitHub repository so you don’t have to start from scratch.
  3. Flash: Connect the WeMos D1 Mini to your computer via USB, and ESPHome will compile and flash the firmware directly. After the initial flash, future updates can be done wirelessly (OTA - Over The Air).

Method 2: Flashing via ESPHome Web Tools (Online Method)

‌‌This method allows you to flash your WeMos D1 Mini directly from a browser, without needing to create files in Home Assistant.

  1. Visit the ESPHome Web Tools: Head over to the ESPHome Web Tools in a supported browser like Chrome or Edge.
  2. Upload Firmware: Select or create the firmware file (such as from my GitHub example linked above ↑↑ ). Connect the WeMos D1 Mini to your computer, and the tool will handle the flashing process directly from your browser.
  3. Configure WiFi: During the flashing process, if you're using the setup wizard, you’ll be prompted to enter your WiFi SSID and password. Alternatively, if you're following my example configuration, your WiFi credentials will already be pre-configured in the secrets.yaml file. This step ensures the WeMos D1 Mini can connect to your network and communicate with Home Assistant.

I’ve added helpful notes in the GitHub configuration file, but if you need more information, you can always check out the ESPHome documentation. Once the firmware is flashed using either of these methods, the WeMos D1 Mini will be able to communicate with Home Assistant.

Step 2: Wiring Your Smart Doorbell

Now that your WeMos D1 Mini is flashed with the firmware, it’s time to wire everything together to make your doorbell smart. Let’s break this process down step by step so it’s easy to follow:

  • Set Up the Relay: In this project, the relay is responsible for controlling the doorbell chime. It operates using 5V, which will be supplied by your WeMos D1 Mini. The relay acts as a switch, allowing or cutting off the electrical signal to the doorbell chime. The doorbell button will be wired as an input to the WeMos D1 Mini, which detects when the button is pressed.
  • Wiring the Doorbell Button: The doorbell button is wired to the D1 Mini as a pulldown input. This means that when the button is pressed, the WeMos detects a signal (voltage goes high), which in turn tells the relay to activate the chime.
  • Connect the Relay to the Chime: Wire the relay to the existing doorbell chime so that it controls the circuit. When the button is pressed, the relay will close the circuit and allow the doorbell chime to ring.
  • Test Your Setup: Once you’ve wired everything, it’s time to test the system. Press the doorbell button. If the chime rings like it did before, congratulations you’ve successfully wired your smart doorbell! The WeMos D1 Mini is now controlling the doorbell, and the firmware is working as expected.

This setup ensures your doorbell continues to function as normal, even if your system is down for any reason, but now you have the ability to integrate smart features through Home Assistant for additional control and automation

Step 3: Integrating With Home Assistant

Here’s where the magic happens. Once your doorbell is wired up and the firmware is flashed, it’s time to integrate it with Home Assistant.

  • Device Naming Convention: I recommend using a clear and consistent naming convention for your devices. For example, use “doorbell” as the domain and follow with the room and entity. This makes managing automations easier down the road as your smart home grows.
  • Discovering Entities: Home Assistant should automatically detect the new entities created by your smart doorbell, such as the doorbell button press. You can now display these entities on a dashboard or create automations with them.

Step 4: Setting Up Automations

A smart doorbell isn’t really smart until you add some automations. Here are a few ideas to get you started:

  • Night Mode: Automatically turn off the chime during certain hours, like during your kids' nap time.
  • Mobile Notifications: Get a notification on your phone when someone presses the doorbell.
  • Smart Speaker Alerts: If you have a smart speaker, you can have it announce when someone is at the door.

The possibilities are endless, and you can customize the automations to suit your needs!

Conclusion

Converting a regular doorbell into a smart one isn’t just a fun project; it’s a useful upgrade that brings your home closer to full automation. By following these steps and making sure your circuit is secure, you’ll end up with a reliable smart doorbell that not only notifies you when someone’s at the door but also opens up endless possibilities for automation. Give it a try, and let me know how your setup turns out!

If you’re looking for more smart home tutorials and projects, be sure to check out the other articles and videos on my Binary Tech Labs YouTube channel and blog. Thanks for reading, and happy automating!

Software & Tools

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