Sonoff USB Dongle 3 plus vs SmartThings hub

Does anyone have any idea why my zigbee light & motion sensor worked faster - considerably faster - when I had them set up on my Smart Things hub vs now being set up on my Home Assistant using my Sonoff USB dongle via a Virtual Machine running on my Synology 920+ (8GB total / 2GB VM)?

I’m gonna guess it’s the difference between a dedicated machine running for no reason outside communicating to Zigbee & Z-Wave devices vs a variety of interpreters from the Sonoff Dongle, to the Synology, to the VM …

But I thought the beauty of Zigbee was that it could use the Light bulb as a router (which according to my Zigbee2MQTT, it does exactly that) connected directly to the sensor. So by rights, surely if the light bulb is the router and is directly talking to the sensor - surely that should work way quicker than when I was the Smart Things hub?

I feel a bit stumped on this - it’s taking several seconds to respond now… whereas back on the SmartThings hub, it was almost instant, considerably less than a second.

Any ideas?

Probably interference in a “noisy” environment where the signal does not always come through. My guess is also that you have it connected to a USB 3.0 port which is known to cause EMF interference.

Regardless of the actual root cause, always aim to keep the firmware of the Zigbee Coordinator adapter updated and more products acting as Zigbee Router devices, however most important is to prioritize taking preemptive actions to implement workarounds in order to avoid all sources of EMF/EMI/RFI interference which can commonly cause real problems for a Zigbee Coordinator. Read:


Understand and remember that Zigbee signals are really weak so rely on a strong Zigbee network mesh (meaning many Zigbee Router devices) as all Zigbee devices and especially the Zigbee Coordinator are very sensitive to EMF/EMI/RMI interference so will make it much easier to troubleshoot and find the real root cause if have already optimized your setup and environment to workaround such potential issues.

If have some interference and a so-called “noisy environment” then Zigbee Coordinator and Zigbee devices will have to retransmit their messages over and over again, spamming the Zigbee network.

Start by getting a long USB extension cable for the Zigbee Coordinator adapter and connect it to a USB 2.0 port (or via a powered USB 2.0 hub if only got USB 3.0 ports as those cause interference).

Also if you have not already then upgrade to latest Zigbee Coordinator firmware on the adapter, read:

Thanks for the insight :slight_smile:

I am using a 2mtr usb extension and it is used to elevate the dongle from the floor to just below the ceiling, which is also where the light and the sensors are situated. The dongle is also physically closer to the devices than the old smartthings hub is (and was), by at least a good 6mtrs. And I updated to the latest firmware as soon as I purchased it.

I think my device (synology 920+) only has USB3 but I’ll double check… I had thought someone had previously suggested USB3 where possible - but it’s very plausible that I simply misread. I’ll have a check on my Synology specs :slight_smile:

Update firmware again if have issues as new firmware with bug-fixes released about every other month.

While USB 3.0 is technically compatible on paper it does not work in practice because of interference so you will at least need to get a powered USB 2.0 hub and connect USB extension after that. Read: