Nabu Casa Has Released the Connect AUX-2

Nabu Casa has released the Connect AUX-2, a compact device designed to integrate legacy audio equipment into modern smart home setups.

The hardware allows users to connect older hi-fi systems, AV receivers, and active speakers directly to the Home Assistant platform.

The device functions as a local, open-source alternative to legacy products like Google’s Chromecast Audio, according to reporting by [Živě.cz]. At its core, the AUX-2 utilizes an ESP32-S3 chip running ESPHome firmware, which ensures direct compatibility with Home Assistant.

Connectivity and hardware features

The AUX-2 features a single 3.5mm jack that handles both analog and optical digital audio output. Beyond basic playback, the device includes two RS-232 serial ports, allowing users to control compatible televisions and AV receivers—such as adjusting volume or switching inputs—directly through local automation without relying on manufacturer clouds.

The hardware also includes a USB-A port, which supports adapters like the Connect ZWA-2 for Z-Wave connectivity or Modbus modules for monitoring solar inverters. The unit acts as a Bluetooth proxy, bridging connections between Home Assistant and nearby Bluetooth devices.

Syncing Audio with Sendspin Protocol

Playback is managed through the Music Assistant server and the Sendspin protocol, which enables multi-room audio synchronization. Users can group multiple AUX-2 units together or integrate them with existing hardware from brands such as Sonos and Apple.

The device supports an unlocked bootloader, permitting users to install custom firmware like Squeezelite or Snapcast. Power and network connectivity can be managed via Power-over-Ethernet (PoE), or users may opt for USB-C and Wi-Fi 4 (2.4 GHz). The unit maintains a power consumption rate of approximately 1 to 2 watts.

Pricing the Connect AUX-2

The Connect AUX-2 is priced at 59 euros including tax. In the Czech Republic, retailers including [Alza] and [SmarterHome] offer the device for 1,649 CZK. The manufacturer notes that the retail package does not include connection cables, which must be sourced separately by the user. Standard operation of the device requires Home Assistant version 2026.9 or later.

Powering the AUX-2 Device

Can the AUX-2 be powered without using PoE? Yes. The device can be powered via PoE or its USB-C port, and it supports network connectivity through Wi-Fi.