Home Assistant Connect AUX-2 adds audio, serial and Bluetooth links to a $69 box

Nabu Casa, the commercial arm of the Open Home Foundation that backs Home Assistant, has launched the Home Assistant Connect AUX-2. The device is a small network box priced at $69. It is designed to bring older audio equipment, serial-controlled devices and Bluetooth gadgets into a Home Assistant setup.

The box measures 106 by 63 by 25 millimetres, according to XDA Developers, and is white and semi-transparent. Inside is an ESP32-S3 chip, a TI PCM5122 converter for analogue audio and a W5500 Ethernet controller that supports power over Ethernet. It also has 2.4 GHz Wi-Fi and accepts USB-C power. No Ethernet or USB-C cable is included in the box.

The unit runs ESPHome with open-source firmware. Home Assistant finds it over Bluetooth, takes Wi-Fi details through Improv and then adds it as an ESPHome device. XDA's reviewer said setup took about five minutes. Users have 15 minutes after power-on to finish, and a power cycle restarts the process if that window is missed. The Verge's reviewer installed the latest firmware from a browser over USB-C.

For audio, there is one 3.5 mm analogue stereo output and an optical S/PDIF output through a mini-TOSLINK cable. Both are limited to 16-bit and 48 kHz. The box detects the cable type and switches mode automatically, though this can be overridden in Home Assistant. The device is output-only. It does not stream Bluetooth audio, and a passive speaker still needs its own amplifier.

Music Assistant acts as the source. It sends audio to the AUX-2 and to other compatible players on the local network. Sendspin, an open standard from the Open Home Foundation, keeps those players in sync without a separate cloud account. XDA's reviewer grouped an older Huawei Sound X with a Sonos Era 100 and reported good synchronisation, which they said beat the DLNA setup they had used before. Music Assistant can also bridge AirPlay and Google Cast speakers into the same groups. Sendspin support for Chromecast devices is still experimental.

The Verge's reviewer used the box for other jobs. Its Bluetooth proxy brought in Govee hygrometers that monitor a garage fridge. The serial ports can control TVs, AV receivers and solar inverters. A USB port takes a Nabu Casa Z-Wave or Zigbee antenna, which helps when the main Home Assistant hub sits in a poor location. A Grove port connects sensors, buttons and LEDs.

The device has cautions. Its three 3.5 mm jacks look identical, but two are RS-232 serial ports that carry 5 V signals. Plugging one into audio gear by mistake could cause damage. The box also depends on Home Assistant and Music Assistant, so buyers without a self-hosted setup face a higher total cost.

Several points are still unclear. The sources do not give regional availability or a shipping date. XDA said Nabu Casa supplied its review unit and had no input into the review. The Verge describes serial support and Music Assistant features as still in active development.