Smart-home maker Nabu Casa has launched the Connect AUX-2, a small box that hooks equipment you already own into Home Assistant. It went on sale worldwide on 11 November for $69 or €59, and it is useless without a Home Assistant setup.
The idea is simple: an old amplifier, a solar inverter or a TV with a serial port is still good, but its app or cloud service may not be. The AUX-2 has a USB-A port, two RS-232 serial ports on 3.5 mm jacks, a Grove sensor port and an audio output, so one small box can reach all of them.
For music, the box has a 3.5 mm output and works out for itself whether an analog or a digital cable is plugged in. Music Assistant, the free companion app, finds it automatically as a Sendspin player and can group it with other speakers, including AirPlay and some Sonos models, to play in sync. Nabu Casa says the box never draws more than a watt or two. It has no audio input and cannot send or receive Bluetooth audio, so it is an output for your stereo, not a speaker in itself.
The serial ports let Home Assistant switch an AV receiver on from standby, change its volume or source, or run a TV without connecting the TV to the internet. In its launch post, Nabu Casa gives an LG TV as the example. The limit is that a device needs an existing Home Assistant integration to be controlled this way, and no serial cables are included. RS-485 and Modbus gear can be reached through the USB port with a $15 adapter.
The box can also act as a Bluetooth proxy that Home Assistant discovers without any flashing, and with Ethernet it no longer shares one antenna between Wi-Fi and Bluetooth. A Connect ZWA-2 Z-Wave stick plugged into it can sit anywhere the network reaches, rather than next to the server in a basement. Zigbee works too, but only through ZHA, and Nabu Casa asks for more testing before it promotes that. Thread is not supported and is not planned.
Power comes from USB-C or from Power over Ethernet, one at a time, and the network link is Ethernet or 2.4 GHz Wi-Fi. Setup needs Home Assistant 2026.9 or later, or 2026.11 for the Zigbee option. The case is held by four screws, and the company says the PCB and 3D print files are coming.
