Home Assistant's $69 Connect AUX-2 Is a Small Box for Making Old Stereos, TVs and Solar Gear Smart

ROHNERT PARK, Calif. - Nabu Casa, the company that makes official hardware for the open-source Home Assistant smart home platform, on Wednesday released the Home Assistant Connect AUX-2, a small box meant to bring older and less connected devices into a modern smart home. It is available worldwide for $69, or 59 euros, the company said in its launch post.

Nabu Casa calls the AUX-2 a “smart home multi-tool.” It can stream audio, control equipment over RS-232 serial ports, extend a Z-Wave adapter across a network and work as a Bluetooth hub. It runs on Power over Ethernet, a feature Home Assistant users have asked for, or on USB power and Wi-Fi. The company unveiled it during a livestream on Wednesday.

Image: Home Assistant

The name explains most of the hardware. AUX stands for audio, USB and X for serial, according to Shay Redmond, a product manager at Nabu Casa, who wrote the launch post. The box began as a simpler idea, a way to run the company’s Connect ZWA-2 Z-Wave and ZBT-2 Zigbee adapters over Power over Ethernet. Because PoE made up most of the cost, Nabu Casa found that adding more ports was “surprisingly affordable.”

The audio side is aimed at hi-fi equipment that still sounds good but has no network connection. Many amplifiers and receivers have an optical digital input and a serial control port. With both connected, the AUX-2 can send lossless, CD-quality sound to the amplifier while handling volume, source and power over serial, even from standby. The jack detects whether an analog or digital cable is plugged in and switches output on its own. Paired with Music Assistant and its Sendspin protocol, several AUX-2 units can play in sync with each other or alongside speakers from other brands, including HomePod and Sonos, the company said. Nabu Casa says the box never draws more than a watt or two.

Image: Home Assistant

The two serial ports are meant for equipment that people are unlikely to replace just because its app is poor, such as solar inverters, climate systems and televisions. Home Assistant already supports a growing list of serial devices. Nabu Casa suggests that owners of LG televisions can cut the set off from the internet and control it through the LG serial integration instead. The ports use 3.5 mm connectors, and switches on the bottom swap the receive and transmit lines so that most cables will work. RS-485 and Modbus devices can be added through the USB port with a separate adapter.

Image: Home Assistant

The USB port also lets owners place a Connect ZWA-2 anywhere the home network reaches, instead of next to the Home Assistant server in a basement. Nabu Casa says it has tested Z-Wave this way for months. Zigbee works too, but the company is not yet advertising it for everyday use and is asking users to test it. Thread does not work, because it is too sensitive to network delay.

Image: Home Assistant

The AUX-2 is also Nabu Casa’s first device built to act as a Bluetooth proxy, picking up Bluetooth sensors and gadgets around the home without a manufacturer’s cloud hub. It begins discovering devices as soon as it is added to Home Assistant. A Grove port accepts simple temperature, humidity or light sensors. As with its other hardware, the company says the AUX-2 is fully unlocked for custom firmware, opens with four Phillips screws and no glue, and will get public circuit board and 3D print files.

Video: Home Assistant on YouTube

Home Assistant announced the launch on X.

Screenshot: @home_assistant on X