To clarify, is it ITead’s “Sonoff Zigbee 3.0 USB Dongle Plus” or their “Zigbee 3.0 USB Dongle”?
Start by updating firmware and use USB extension cable as might not make proper connection without:
- First batch came pre-flashing with older firmware from 20210120 which works out-of-the-box with ZHA and Zigbee2MQTT, however, it is highly recommended to at least upgrade to firmware Z-Stack 3.x.0 build 20211217 or later
- Other than many bug-fixes the newer firmware offer +9dBm transmission power instead (instead of +5dBm transmission power) as well as the possibility to configure up to +20dBm transmission power via software settings in ZHA integration and Zigbee2MQTT respectively.
- To avoid EMF interference strongly recommended buy and use → Long USB extension cable
- Another reason for using a USB extension cable is that the USB-plug design of ITead’s Sonoff Zigbee 3.0 USB Dongle Plus hardware adapter is a little short which makes it harder and sometimes impossible to plug it into some USB ports if the computer enclosure/chassis/casing is to thick around the USB-port as that will physically prevent the USB dongle from actually making a proper connection inside the USB port even if it looks like it is plugged in all the way that is possible.
- Also follow general tips in https://github.com/home-assistant/home-assistant.io/pull/18864 and https://www.home-assistant.io/integrations/zha#best-practices-to-avoid-pairingconnection-difficulties as all Zigbee Coordinator adapters is very sensitive to EMI/RFI interference (e.g. a noisy radio frequency environment will jam the signal and prevent it from receiving all Zigbee messages to it without errors). Connecting the dongle via a long “shielded” USB extension cable in a USB 2.0 port or USB 2.0 hub (and not a USB 3.0 port) to get it away from EMF sources will usually help a lot if experiencing connection or pairing symptoms/issues.
- Win/Mac need Silabs drivers → CP210x USB to UART Bridge VCP Drivers - Silicon Labs
- ITead official FW flashing guide → SONOFF Zigbee 3.0 USB dongle plus firmware flashing
- Unofficial FW flashing without open case → https://github.com/JelmerT/cc2538-bsl/pull/114
- Dongle hardware can also be used as Zigbee router (a.k.a. repeater) → flash router firmware
PS: Many more tips and discussions about ITead’s “Sonoff Zigbee 3.0 USB Dongle Plus” here: