What has changed with the Connect AUX-2 launch?
On 11 November 2026 Nabu Casa, the company behind official Home Assistant hardware, launched the Connect AUX-2 as a "smart home multi-tool" under the tagline "No device left behind". It is a small ESP32-S3 box (106 × 63 × 25 mm, 104 g) built on ESPHome, with an unlocked bootloader so you can flash your own firmware. The recommended price is $69 excluding tax, or €59 including tax, and Nabu Casa says it is available worldwide from launch day.
The ports are the point. Here is what is on the box:
| Feature | What it does |
|---|---|
| Audio output | Combined analogue / optical (S/PDIF) 3.5 mm jack, one at a time; TI PCM5122 DAC; 16-bit/48 kHz stereo |
| Serial | Two 3.5 mm RS-232 ports with TX/RX swap switches; RS-485 / Modbus via a separate USB adapter |
| USB-A | Hosts a Connect ZWA-2 (Z-Wave) or an RS-485 adapter |
| Bluetooth | Bluetooth 5 LE proxy with a dedicated antenna, no flashing needed |
| Grove port | GPIO and I2C sensors, surfaced through ESPHome |
| Power and network | USB-C (5 V, 2 A) or 802.3af PoE; Ethernet or 2.4 GHz Wi-Fi |
It plays audio through Music Assistant, which finds it automatically as a Sendspin player, and Sendspin lets several AUX-2 units, or an AUX-2 plus supported AirPlay and Sonos speakers, play in sync. Nabu Casa says the box never draws more than a watt or two.
Why does the Connect AUX-2 matter for Home Assistant users?
It matters because it is the first official, plug-and-play route for equipment that has no Wi-Fi or Matter. A hi-fi amplifier with an optical input and an RS-232 port can become a Music Assistant speaker whose power, source and volume Home Assistant controls, even from standby. A TV, AV receiver, UPS, climate controller or solar inverter with a serial port can be controlled locally, as long as Home Assistant already has an integration for that device.
Three practical uses stand out:
- Classic stereo into multi-room audio. Digital output into a good amplifier, grouped with other speakers through Music Assistant. Our multi-room audio setup guide covers the speaker side.
- Z-Wave where the signal is best. A ZWA-2 normally has to sit in a USB port beside your server. On an AUX-2 it can live anywhere with an Ethernet cable, which helps if Home Assistant is in a cupboard or basement. See our Z-Wave guide for the UK for the basics.
- A Bluetooth proxy that needs no flashing. It adds a purpose-built Bluetooth proxy, so it is a ready-made alternative to the DIY ESP32 approach in our Bluetooth proxy guide.
The serial side also suits energy monitoring. Nabu Casa pitches it for old solar or climate gear, and a UPS with a serial port fits the monitoring approach in our UPS for Home Assistant guide.
What can't the Connect AUX-2 do?
Several limits are worth knowing before you buy, all from Nabu Casa's own FAQ and launch post:
- Audio output only. There is no audio input, and it cannot send or receive Bluetooth audio.
- No cables included. The box contains only the unit, a quick-start guide and safety information, so you buy serial and audio cables yourself.
- Serial needs an integration. It only controls serial devices that already have a Home Assistant integration.
- Zigbee is experimental. It works only with ZHA, not Zigbee2MQTT, and needs Home Assistant 2026.11 or later. Nabu Casa is not advertising it for everyday use yet.
- No Thread. Thread is too latency-sensitive to run over a network link, and it is not planned.
- Home Assistant 2026.9 or later is required, and the device is added through the ESPHome integration.
Nabu Casa also recommends a wired connection for Z-Wave and Zigbee; Wi-Fi works but risks instability.
UK availability and price
Nabu Casa's launch page lists UK-shipping resellers, including The Pi Hut and Pimoroni, and says distributor pages may take a few days to go live and stock may be limited. We could not confirm a sterling price at either retailer on launch day, so treat the $69 / €59 figure as the guide: the official price excludes US sales tax and includes EU VAT, and UK retailers set their own prices. If you want to use it as a ZWA-2 extender you will also need the ZWA-2 itself.
Should you buy the Connect AUX-2 now or wait?
Buy now if you already own the gear it targets: a hi-fi with optical input, a serial-capable AV receiver or TV, or a Z-Wave stick stuck in a bad spot. Wait if you want Zigbee over the network, because Nabu Casa itself says that needs more testing, or if your use case is Thread, which will not work. If you only want a Bluetooth proxy, a cheap DIY ESP32 build still costs less, though the AUX-2 needs no flashing. For the stick itself, see our Connect ZBT-2 review.
