SMLIGHT SLZB-Ultima is an ESP32-S3-based, multi-radio smart-home gateway with dual Zigbee/Thread radios, optional Z-Wave 800, Wi-Fi, Bluetooth LE, Ethernet with PoE, USB host expansion, and optional 4G LTE connectivity designed for advanced Home Assistant and DIY applications.
The device also integrates an IR receiver and transmitter for controlling legacy appliances, GPIO and I²C for hardware expansion, a buzzer, physical buttons, service LEDs, and 12 on-board WS2812B RGB LEDs on the front for status indication. These features make it suitable for an all-in-one smart-home and IoT gateway rather than a simple coordinator.
SMLIGHT SLZB-Ultima specifications:
- Main SoC – ESP32-S3
- CPU – Dual-core LX7 microprocessor @ up to 240 MHz with Vector extension for machine learning
- Wireless – WiFi 4 and Bluetooth 5 with LE/Mesh
- Audio – Built-in buzzer and optional microphone for ESPHome Voice Assist
- Networking
- Â Wireless
- Dual Zigbee / Thread radios (Texas Instruments CC2674P10 + Silicon Labs EFR32MG24)
- Wi-Fi 802.11 b/g/n (2.4 GHz) and Bluetooth LE via ESP32S3
- Optional Z-Wave 800 add-on module (Z-Wave JS over Ethernet or USB)
- USB Host supports external Zigbee, Thread, or Z-Wave USB dongles
- Optional 4G / LTE add-on via A7672G module for primary or backup WAN
- Ethernet – Ethernet RJ45 port with optional Power over Ethernet (PoE) add-on
- 4x antennas for Z-wave, CC26xx (Zigbee/Thread), EFR32MG (Zigbee/Thread), and 4G LTE
- Â Wireless
- USB
- USB Type-A port for external dongles or peripherals
- USB Type-C port for external dongles or peripherals
- USB Type-C port for power and data/flashing (backside)
- Expansion – Internal headers for I2C & GPIO sensors
- Misc
- 12× WS2812B addressable RGB LEDs
- 3x physical buttons
- 4x service/status LEDs
- Built-in IR transmitter and receiver
- Power
- 5V via USB Type-C port
- PoE via an optional add-on
- UPS Add-on support for power outage protection
- Dimensions – TBD
After taking a closer look at the images, I can see there is a microSD card slot on the left side, two USB Type-C ports on the front, and a third USB-C port on the rear, a total of three USB-C ports. The company does not clearly mention the application for the third one at the front. There also seems to be a 3.5 mm audio jack, but it is not clear if that port is for the optional microphone add-on.
In terms of software support, the SLZB-Ultima runs on SLZB-OS, which works with Home Assistant, Zigbee2MQTT, and ZHA. It features built-in tools like WireGuard VPN for secure remote access, an internal Zigbee hub for standalone setups, and supports over-the-air updates. On top of that, the device also works with ESPHome, with features like Bluetooth Proxy and native integration for a highly customizable smart home experience.
Previously, we have written about other SMLIGHT products like the SLZB-06p7/SLZB-06p10, which add Ethernet and PoE connectivity to Zigbee networks. But this new device can be considered as an alternative to the SONOFF Dongle Max and the cod.m Zigbee Coordinator 1.0 as it has a multi-radio interface with support for PoE, Wi-Fi, Bluetooth LE, USB host expansion, and support for standalone operation or Home Assistant–based deployments.
The SMLIGHT SLZB-Ultima multi-radio gateway is available on AliExpress in multiple hardware configurations. The base Zigbee/Thread model is priced at US $46.77, whereas the fully featured U3-PoE-Z-Wave-4G-Mic variant costs US $83.47. Configuration options include PoE, Z-Wave 800, 4G/LTE, and an optional microphone module, offered in different combinations. It’s also available on the SMLIGHT online store at similar price points and with the same set of configurations.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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