SMLIGHT SLZB-MR1U Dual-Radio Adapter Zigbee and Thread with Ethernet, Wi-Fi, PoE and USB Passthrough

SMLIGHT SLZB-MR1U Dual-Radio Zigbee and Thread Coordinator

One adapter for both Zigbee and Thread: the SMLIGHT SLZB-MR1U combines two independent radios in one housing. The proven Texas Instruments CC2652P powers your Zigbee 3.0 network, while the Silicon Labs EFR32MG21 runs in parallel as a Thread Border Router for Matter devices. Both protocols operate simultaneously, fully locally, and without cloud dependency, connected via Ethernet, Wi-Fi, or USB-C to Home Assistant. Plug in, pair, done.

Chipsets and Hardware

The SLZB-MR1U runs on three specialized chips: the Texas Instruments CC2652P handles the Zigbee 3.0 radio with +20 dB output gain, the Silicon Labs EFR32MG21 processes Thread and Matter-over-Thread, and the ESP32 manages all network and configuration functions via SLZB-OS. The included external SMA antenna (+5 dB, rotatable) ensures stable range. Four status LEDs on the PCB provide direct feedback on connection and status.

Connectivity and Power

The SLZB-MR1U supports Ethernet (10/100 Mbit/s via RJ45), Wi-Fi (2.4 GHz), and USB Type-C as connectivity options. Power is supplied via USB-C (5V) or Power over Ethernet (IEEE 802.3af, 48V PoE); both can be connected simultaneously thanks to optoelectronic isolation. When using Wi-Fi, pay attention to channel selection: Zigbee, Thread, and Wi-Fi share the 2.4 GHz band and can interfere with each other if channels overlap. Ethernet is the recommended connection method for maximum stability.

USB Passthrough

The SLZB-MR1U (the U version) features a USB passthrough function: connect a third USB dongle to the extra USB port and use that dongle over the network as if it were directly connected to your server. This works with commonly used USB-to-UART chips such as CP210x, CH340, and CH9102. With PoE power, the USB port also supplies power to the connected dongle. The SLZB-MR1 without U does not have this feature; please check the model number carefully before purchase. Also check out our other Zigbee USB coordinators for alternatives.

SLZB-OS and Firmware Modes

The SLZB-MR1U comes with SLZB-OS: SMLIGHT's proprietary operating system with a built-in web interface for configuration, one-click firmware updates for the ESP32 core and both radios (CC2652P and EFR32MG21), WireGuard VPN, DDNS, OTA updates, and hardware diagnostics. The two radios are fully independently configurable: the CC2652P runs as a Zigbee Coordinator (ZHA/Zigbee2MQTT) or Zigbee Router, the EFR32MG21 runs as a Thread/Matter Border Router (OTBR). ESPHome firmware is also supported for use as a Bluetooth proxy.

Home Assistant

The SLZB-MR1U works via Zigbee2MQTT and ZHA for the Zigbee network (CC2652P) and via the OpenThread Border Router add-on for the Thread/Matter network (EFR32MG21), fully locally without the cloud. The official SMLIGHT SLZB integration in Home Assistant provides direct monitoring, diagnostics, and firmware updates from the HA dashboard for both radios. Local control is confirmed; the cloud is not required after pairing.

Pairing Procedure Zigbee via Ethernet and Zigbee2MQTT

• Connect the SLZB-MR1U via Ethernet to your router; power via PoE or USB-C.
• Open the SLZB-OS web interface via the IP address (visible in your router) or via mDNS: http://slzb-mr1.local.
• Confirm that the CC2652P radio is active as a Zigbee Coordinator; note the IP address and port (default 6638).
• In HA, go to Zigbee2MQTT > Settings > Serial and choose Network device; enter as tcp://[ip-address]:6638.
• Zigbee2MQTT recognizes the CC2652P as a ZNP coordinator; the Zigbee network is immediately operational.

Pairing Procedure Thread/Matter via OpenThread Border Router

• Enable the EFR32MG21 as a Thread OTBR radio via SLZB-OS.
• Install the OpenThread Border Router add-on in Home Assistant.
• Select the SLZB-MR1U as the network border router via the IP address and port for Thread (default 8080 or 6638 on a separate channel; check SLZB-OS).
• The Thread integration will automatically appear in HA; Matter devices can be paired directly via the Matter integration in HA.

Pairing Procedure via ZHA

• In HA, go to Settings > Devices & services > ZHA > Add integration.
• Choose Network device and enter socket://[ip-address]:6638.
• ZHA will automatically detect the CC2652P; the Zigbee network will be active within seconds.

Other Platforms

The SLZB-MR1U works on any platform with ZNP support (Zigbee) or OTBR support (Thread) via Ethernet, Wi-Fi, or USB: Home Assistant, ioBroker, openHAB, HomeSeer, and Node-RED. Drivers are available for Windows, Linux, macOS, and Raspberry Pi OS.

Automation Examples

Example 1 – Monitoring Zigbee and Matter in parallel and reporting outages

• Install the official SMLIGHT SLZB integration in Home Assistant.
• Trigger: status of the SLZB-MR1U Zigbee or Thread radio becomes unavailable and persists for more than 3 minutes.
• Action 1: restart the affected add-on (Zigbee2MQTT or OpenThread Border Router) via service hassio.addon_restart.
• Action 2: send a push notification stating which radio has failed and that recovery has started.

Example 2 – Mixed automation: Zigbee sensor triggers Matter lamp

• Trigger: motion sensor (Zigbee, via Zigbee2MQTT) detects movement in the hallway.
• Condition: time is between 22:00 and 07:00 and lux sensor reports less than 10 lux.
• Action 1: dim the Matter lamp in the hallway via the Matter integration to 30%.
• Action 2: automatically turn off the lamp after 3 minutes if no further movement is detected.

Points of Attention

• The SLZB-MR1U (with U) has USB passthrough; the SLZB-MR1 (without U) does not have this function. Check the model number carefully before purchase.
• Wi-Fi, Zigbee, and Thread all operate at 2.4 GHz; when using Wi-Fi, pay attention to channel selection to avoid interference. Ethernet is the recommended connection for maximum stability.
• PoE standard IEEE 802.3af (48V) required; check if your switch or injector supports this standard.
• The CC2652P supports approximately 150 Zigbee devices per coordinator. For larger installations, multiple Zigbee2MQTT instances with separate coordinators are required.
• ESPHome Bluetooth proxy firmware temporarily replaces SLZB-OS on the ESP32 core; resetting is done via the built-in web interface.

Contents of the Box

• 1x SMLIGHT SLZB-MR1U dual-radio network adapter
• 1x +5 dB external SMA antenna (rotatable)
• 1x user manual / QR code card

Compatibility

Compatible with Home Assistant (ZHA, Zigbee2MQTT, OpenThread Border Router add-on and official SMLIGHT SLZB integration), ioBroker, openHAB, HomeSeer, and Node-RED. Connection via Ethernet, Wi-Fi (2.4 GHz), or USB. Supports all Zigbee 3.0 devices and Matter/Thread devices in our assortment, including sensors, switches, and smart plugs.

Specifications

Frequently Asked Questions

What is the difference between the SLZB-MR1U and the SLZB-MR1 (without U)?

The only difference is the USB passthrough function. The SLZB-MR1U (with U) has an extra USB port for a third dongle over the network. The SLZB-MR1 (without U) does not have this port. Both models have two independent radios (CC2652P and EFR32MG21) and identical connectivity options. Check the model number carefully before purchase.

Can I use Zigbee and Thread simultaneously on the SLZB-MR1U?

Yes. The CC2652P and EFR32MG21 are two completely independent radios in the same housing. In Home Assistant, you can run Zigbee2MQTT (or ZHA) for Zigbee and the OpenThread Border Router add-on for Thread/Matter in parallel, without one radio affecting the other.

Do I need an Ethernet cable to use the SLZB-MR1U?

Not for daily use: the adapter also works via Wi-Fi (2.4 GHz) or USB. An Ethernet cable is useful for initial setup to access the SLZB-OS web interface and enter any Wi-Fi settings. Ethernet remains the recommended connection method for maximum stability, especially with two active radios at 2.4 GHz.

How do I perform firmware updates for both radios?

Updates for the ESP32 core, the CC2652P Zigbee radio, and the EFR32MG21 Thread radio can all be performed via the built-in SLZB-OS web interface with one click per radio, without removing the adapter. Home Assistant users can also perform updates directly via the official SMLIGHT SLZB integration in the HA dashboard.

Can I use the SLZB-MR1U as a Thread Border Router for Matter?

Yes, the EFR32MG21 radio runs as a Thread OTBR by default. Install the OpenThread Border Router add-on in Home Assistant and select the SLZB-MR1U as the network border router. Matter devices can then be paired directly via the Matter integration in HA, while the CC2652P simultaneously manages your entire Zigbee network.

Does the SLZB-MR1U work with Homey?

No, the SLZB-MR1U is an external multi-radio coordinator for platforms such as Home Assistant, ioBroker, and openHAB. Homey has its own built-in Zigbee radio and does not work with external coordinators. For a Homey setup, you do not need a separate coordinator.

Does the USB passthrough also work with PoE power?

Yes. With PoE power, the USB port of the SLZB-MR1U also supplies power to the connected USB dongle. A separate power source for the dongle is not required. The USB passthrough works with common USB-to-UART chips: CP210x, CH340, and CH9102.

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