Nabu Casa — the commercial side of the Open Home Foundation, which runs Home Assistant — just launched the Home Assistant Connect Aux-2, a multi-function box designed to help you bring more non-smart devices into your smart home. It’s part of Home Assistant’s ongoing efforts to become more user-friendly. And it’s working.
I’ve been testing the Aux-2 for a couple days and I’ve found it unsurprisingly useful and surprisingly easy to set up. The Aux-2 is a $69 box about the size of a deck of cards.
It has 2.4GHz Wi-Fi, Bluetooth, Ethernet, USB-A, USB-C, a digital/analog audio jack, a Grove port for interfacing with peripherals like sensors, buttons, and LEDs, and a pair of RS-232 serial ports. [Image: https://platform.theverge.com/wp-content/uploads/sites/2/2026/11/aux2-front.jpg?quality=90&strip=all] [Image: https://platform.theverge.com/wp-content/uploads/sites/2/2026/11/Aux-2-rear.jpg?quality=90&strip=all]
It can bridge Bluetooth devices into your Home Assistant setup.
Its USB port lets you plug in a Nabu Casa Z-Wave or Zigbee antenna in case your Home Assistant hub isn’t in a good spot. You can control devices like TVs, AV receivers, solar inverters, and more via serial connector. And you can connect an amplifier or powered speakers to its audio jack to stream music to older audio equipment. All of these things leverage Home Assistant’s capabilities as an open-source platform.
The Aux-2 is based on ESPHome, an open platform for making DIY smart home devices from cheap, flexible ESP boards, and it uses existing Home Assistant/ESPHome integrations for all its features. The serial integration was developed earlier this year; Music Assistant and SendSpin, which power the audio-out feature, are in active development.
I have a Home Assistant install, but even after several years it is not my primary smart home platform simply because of friction and time constraints. Instead, I have a hodgepodge of Google Home, Apple Home, and a few devices that are only in Home Assistant. The situation is not ideal.
But the Aux-2’s capabilities perfectly intersect with two things I’d been meaning to do anyway, one of which I’m already using Home Assistant for. First, I have a garage fridge, because I live in Texas. I also have children, which means sometimes the fridge or freezer door gets left open. I want to know when that happens before all my food goes bad.
A couple years ago, I set up a few Aqara temperature sensors, connected to Home Assistant via a now-discontinued Zigbee dongle, and set up an automation to alert me if the fridge or freezer get too warm.
But they frequently drop connection (probably because they’re inside a fridge in the garage), they chew through coin cell batteries, and they have no displays, which means I also have a cheap Acu-rite hygrometer in the fridge so I can see the temperature without pulling out my phone. Someone tipped me off to Govee’s Bluetooth hygrometers, but I’d need a Bluetooth proxy to get them into Home Assistant.
That happens to be a feature of the Aux-2. I also have a set of in-wall speakers in my living room that I’ve never used. I’d been meaning to get an amp, but analysis paralysis set in. Do I get a Wiim Amp? A stereo receiver? A cheap Bluetooth amp? Do I try to get them to work with my four Sonos speakers? Maybe my ancient Google Home speaker? Turns out I do nothing for five years. Maybe the Aux-2 could help.
Setting up the Aux-2 was much easier than I expected. I plugged it into my computer via USB-C and…
