Typically associated with circuitry projects and real-time operating systems, microcontrollers are great for tinkerers who prefer working with embedded devices. But unlike their SBC counterparts, you might not find much use for them in typical home lab experiments. That is, unless the microcontroller in question happens to be an ESP32.

Thanks to the ESPHome utility, ESP32 systems can double as amazing experimentation hubs for smart home devices. Whether it’s displaying your Home Assistant dashboard via ePaper or building a wacky setup that powers itself on when it detects vibrations nearby, there’s a lot you can do with an ESP32 for your home lab. A Bluetooth Proxy is one such project, and here’s everything you need to know before building it with an ESP32.

What’s a Bluetooth Proxy?

And where does an ESP32 fit into all this?

When you’ve set out to assemble a formidable smart home setup, you’ll probably use Wi-Fi, Zigbee, and a host of other protocols to communicate with your IoT paraphernalia. But at some point, you’ll encounter devices that rely on Bluetooth as their sole connection protocol. If your Home Assistant rig isn’t armed with a Bluetooth adapter, you’ll have a hard time pairing these devices to your HASS instance.

That’s where a Bluetooth Proxy comes into the picture. It essentially acts as a medium between your Bluetooth (and Bluetooth Low Energy) devices and your Home Assistant interface, allowing the latter to establish a communication line with your IoT paraphernalia without forcing you to buy a dedicated adapter.

Since most ESP32 microcontrollers are armed with both Wi-Fi and Bluetooth capabilities, they serve as amazing Bluetooth Proxies. Once you set them up properly, these proxies pick up Bluetooth signals from your smart devices and forward them to your Home Assistant via Wi-Fi, thereby leveraging both communication protocols to let your IoT paraphernalia communicate with your HASS configuration.

What are the perks of a Bluetooth Proxy?

It has an amazing range

Besides the obvious advantage of enabling Bluetooth capabilities for your Home Assistant interface, an ESP32-powered proxy allows you to control and automate smart devices over a large area. I’ve got my Home Assistant rig chugging along in the basement. Even with a normal Bluetooth adapter, my HASS server won’t be able to communicate with the devices in the attic, lawn, and other recesses of my home.

Since an ESP32 Bluetooth Proxy supports wireless communication, I don’t have to hook it up to the basement-dwelling home server. Thanks to their compact size, I can hide these microcontrollers anywhere in my living room and use them to control the Bluetooth paraphernalia in my smart home setup.

Building a Bluetooth Proxy using an ESP32

Plenty of ways to do so

With the theory part over, it’s time to look at the practical aspect of this setup. As with other home lab experiments, there are tons of methods to convert an ESP32 into a Bluetooth Proxy. Since I want to use it with my Home Assistant server, I used the ESPHome add-on method.

If you’ve already got a working HASS configuration, you can find the ESPHome module inside the Add-on Store. Once you’ve installed this add-on, you can launch its web UI and plug the ESP32 into your client machine. Depending on your specific model, you may need to install the CP2102 or CH340 drivers and use the Driver Manager to update the ones automatically loaded by Windows.

Back on the ESPHome web UI, pressing the New device button will display a pop-up containing the serial port of your ESP32, and clicking on it will bring up another window. Tapping the Install button should flash the ESP32 with the code necessary to connect it to your ESPHome instance. However, I had to press and hold the Boot button on my ESP32; otherwise, it would show an error.

After the ESP32 is paired with ESPHome, you can hit the Config button and append the following code to the boilerplate config file:

esp32_ble_tracker:
scan_parameters:
active: true
bluetooth_proxy:
active: true

Since it’s a YAML file, you’ll want to set up the correct indentation for it. Be sure to update the Wi-Fi credentials inside the configuration file before flashing the new code to the ESP32.

If you’ve performed all the steps correctly, you’ll spot the ESP32 Bluetooth Proxy within the Devices and Services tab of the Settings option inside Home Assistant. Simply press the Add button and wait for HASS to finish pairing your newly-configured Bluetooth Proxy with your smart home setup.

There’s a lot you can do with a Bluetooth Proxy

As someone who relies primarily on Wi-Fi and LAN for connecting smart devices with Home Assistant, I was surprised at the sheer number of IoT products that use Bluetooth for communication. All of a sudden, I had moisture sensors, smart locks, humidifiers, and a ton of other devices popping up in my Home Assistant dashboard.

Heck, folks with smart toothbrushes might even be able to connect them with HASS. If you feel brave enough, you can even use your Bluetooth-powered toothbrush to control your smart devices and home lab!