Specifications and resources – Nabu Casa Support

Product


SoC	ESP32-S3R8, 8 MB PSRAM, 8 MB flash
Audio DAC	TI PCM5122 (112 dB SNR)
Ethernet	W5500
Power	USB-C 5 V ⎓ 2 A Power over Ethernet (802.3af or better) Power draw under 1 W (typical)


Connectivity	3.5 mm audio output, analog or optical S/PDIF (one at a time), output only
Analog	16-bit / 48 kHz stereo
Digital	16-bit / 48 kHz stereo
Codecs	Music Assistant converts audio before sending it over Sendspin, so you can play any format it supports. Decoded on the device: FLAC, MP3, WAV.
Sendspin	Yes, native Sendspin player. On by default. Plays synchronized audio from any Sendspin source, such as Music Assistant.
Bluetooth audio	Not supported


RS-232 Port 1 and Port 2	3.5 mm RS-232 (±5 V), with TX/RX switch
USB-A: Connect radio adapter	One at a time: Connect ZWA-2 (Z-Wave), or Connect ZBT-2 (Zigbee). Zigbee through a Connect ZBT-2 is an experimental feature. Connect ZBT-1 isn't currently supported. See Using a Connect ZBT-2 with Connect AUX-2.
USB-A: USB-to-serial dongle	Waveshare USB TO RS485 (B) only. Exposed as an RS-485 serial proxy.


Wireless	Wi-Fi (2.4 GHz, 802.11b/g/n) Bluetooth 5 (LE)
Wired	Power over Ethernet (PoE, 802.3af or better) Ethernet (USB-C power required)
Bluetooth proxy	Bluetooth Low Energy (BLE) only Up to 3 active connections at a time. Passive BLE sensors don't count toward this limit.
Thread	Not supported


Built for Home Assistant	Yes
Built on ESPHome	Yes
Unlocked bootloader	Yes, can be flashed with custom firmware
Firmware source	NabuCasa/aux-2 on GitHub, everything needed to build the complete firmware


Dimensions & weight	106 × 63 × 25 mm, 104 g
Boxed dimensions & weight	110 × 72 × 28 mm, 136 g
Enclosure	Polycarbonate plastic; white and semi-transparent
Operating conditions	Indoor use only; 0–65 °C (32–149 °F); non-condensing humidity; keep dry, out of direct sunlight and heat