TL;DR
Nabu Casa has launched the $69 Home Assistant Connect Aux-2, a compact device that adds connections such as Bluetooth, audio and serial control to a Home Assistant setup. In a hands-on test, Bluetooth sensor monitoring and audio playback worked after setup, while serial control was not tested and Sendspin remains in development.
Nabu Casa, the commercial arm of the Open Home Foundation, has launched the $69 Home Assistant Connect Aux-2, a small device intended to connect more equipment to Home Assistant. In a hands-on report for The Verge, the reviewer found it relatively easy to set up and used it to bring Bluetooth temperature sensors into Home Assistant and play music through older wired speakers.
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The Aux-2 is about the size of a deck of cards and includes 2.4GHz Wi-Fi, Bluetooth and Ethernet, along with USB-A and USB-C, an audio jack, a Grove port for peripherals and two RS-232 serial ports. Its functions include acting as a Bluetooth proxy, providing a connection point for compatible Zigbee or Z-Wave antennas, and linking serial-equipped devices such as TVs, receivers and solar inverters to Home Assistant. The audio jack can connect to an amplifier or powered speakers.
The reviewer set the unit up by connecting it to a computer over USB-C, installing firmware through a browser and entering Wi-Fi details. Home Assistant then discovered the Aux-2 through ESPHome and presented setup steps for its capabilities. The reviewer enabled Bluetooth proxying, added Govee’s Bluetooth integration and found that the sensors appeared automatically. They reported that the connection held through three walls and a refrigerator.
For audio, the reviewer connected in-wall speakers to a separately purchased amplifier and configured Music Assistant, which runs on Home Assistant hardware and supports multiple music services and playback devices. The setup took less than half an hour, according to the report. The reviewer was able to play music through the wired speakers, but had not yet managed to group them with other speakers using Sendspin, an audio standard still under development.
More Devices Within Home Assistant
The Aux-2’s appeal is that it can address several connection problems with one Home Assistant-compatible device. A Bluetooth proxy can bring nearby sensors into a system even when the main hub is poorly positioned. Audio connections can make existing wired speakers usable, while serial ports offer a route to controlling or monitoring equipment that may not have modern smart-home connectivity.
The hands-on test also speaks to a persistent trade-off for Home Assistant users: the platform is flexible, but setting up and maintaining devices can take time. The reviewer described using a mix of Google Home, Apple Home and Home Assistant partly because of that friction. The Aux-2’s guided setup and use of existing integrations may lower the effort for some tasks, though one test cannot establish how well every supported device or feature will work.
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Built on ESPHome Integrations
The Aux-2 is based on ESPHome, an open platform for building and connecting devices using ESP boards. Rather than introducing separate software for every function, the unit uses existing Home Assistant and ESPHome integrations. Nabu Casa is the commercial side of the Open Home Foundation, which runs Home Assistant.
The reviewer’s examples came from practical gaps in an existing setup. Aqara temperature sensors used to monitor a garage refrigerator and freezer had frequently lost connection, while Govee Bluetooth hygrometers required a Bluetooth proxy to appear in Home Assistant. The reviewer also had unused in-wall speakers and had delayed choosing an amplifier. The Aux-2 helped with those specific needs, but the results are based on that installation and equipment.
Support for audio and serial control is at different stages. The report says the serial integration was developed earlier in 2026. Music Assistant and Sendspin, which support the audio feature, are in active development. Those distinctions matter: a listed capability does not mean every related workflow is finished or has been tested in the report.
““unsurprisingly useful and surprisingly easy to set up””
— The Verge reviewer
Serial and Grouped Audio Untested
The report does not establish how well serial control works in practice: the reviewer had not tested that feature. It is also unclear whether the unsuccessful attempt to group speakers through Sendspin resulted from setup, the reviewer’s configuration or the standard’s development status. The reviewer said Sendspin remains in development and had not determined the cause.
The review does not test every Aux-2 connection or supported device, and it does not report long-term reliability, power use or performance across a range of Home Assistant installations. The reviewer also wanted the Aux-2 to appear as an AirPlay or Spotify Connect target, but had not set that up. Those outcomes should not be treated as confirmed product limitations or capabilities based on the report alone.
Further Testing Will Clarify Support
The next useful test would be whether serial connections reliably control or read data from equipment such as receivers, TVs and solar inverters. Further use could also clarify how Sendspin grouping works as development continues and whether the Aux-2 can appear as an AirPlay or Spotify Connect target with additional configuration.
For now, the hands-on findings support a narrower conclusion: Bluetooth sensor access and audio playback worked in the reviewer’s setup, while other advertised functions remain untested or dependent on developing software. Prospective buyers will need to check that their devices and desired workflows are supported by the relevant Home Assistant integrations.
Key Questions
What is the Home Assistant Connect Aux-2?
It is a $69 multi-connection device from Nabu Casa that adds capabilities such as Bluetooth proxying, audio output and serial connections to a Home Assistant setup.
What worked in the hands-on test?
The reviewer set up Bluetooth proxying and connected Govee Bluetooth temperature sensors to Home Assistant. The reviewer also used Music Assistant to play music through in-wall speakers connected to an amplifier.
Was serial control tested?
No. The reviewer described serial control as an intriguing feature but said they had not had time to test it. Its real-world performance is not established by this report.
Does the Aux-2 support grouped whole-home audio?
The report says Sendspin is intended to support grouping speakers from different protocols under certain conditions, but the reviewer did not get grouping to work. Sendspin is still in development, and the cause of the setup issue was unclear.
How difficult was setup?
The reviewer installed firmware through a browser, entered Wi-Fi details and completed the remaining setup in Home Assistant. Bluetooth setup took a few clicks; the audio setup took less than half an hour, including configuring Music Assistant and connecting speakers to an amplifier.
Source: theverge.com
