ITead (of Sonoff fame) has announced that will soon sell an inexpensive Zigbee 3.0 USB dongle based on Silicon Labs EFR32MG21 which is a very powerful MCU with an integrated +20 dBm radio amplifier:
Note! Read all updates as the real-life test shows it has hardware issues that need some workarounds:
Update 2021-04-21: People are reporting EMF/EMI/RFI interferences issues causing serious problems with signal reception and especially Zigbee device pairing failures with the initially released hardware revision (HW version “V1.3 2020-12-07”) unless at least use it with a long USB extension cable to get it away from other electronic devices/appliances that are sources of electromagnetic interference and strong radio signals on the same frequency range/band. It is therefore strongly recommended also buy/use a long USB extension cable to get it away some distance from interference made by the computer, other appliances, Wi-Fi access-points or WiFi router. The root cause for this seems to likely be due to a combination of poor antenna design and a lack of electromagnetic shielding in the current design of the initial hardware, (and is maybe something that also can perhaps could be worked around by adding your own DIY electromagnetic shielding to the dongle board by applying a layer of conductive metallic tape over a layer of isolated tape, making sure to ground the conductive metallic tape to USB plug outer metal cover, see idea).
Update 2021-04-16: Pre-flashed firmware it comes with has a bug so requires FW upgrade before use.
Update 2021-03-16: ITead has manufactured a limited production run and now sell it for $6.99 (US):
ITead Zigbee 3.0 USB Dongle Model: 9888010100045 (Hardware Revision Version 1.3)
They have posted a video on ITead’s Facebook group for Sonoff showing this new dongle working out-of-the-box with the ZHA integration for Home Assistant (via the bellows radio library for its zigpy dependecy), however since it will come with the standard Silabs EmberZNet (a.k.a. “Ember”) Zigbee NCP coordinator firmware with its default EZSP serial protocol interface enabled so I believe that it should also work out-of-the-box with OpenHAB Zigbee Bindings too if it now supports EZSP v8?
In that video, they mention that they are targeting DIY home automation users and testing Silabs EmberZNet 18.104.22.168 firmware on it to ship it pre-slashed for compatibility with ZHA for Home Assistant. EmberZNet 6.7 introduced EZSP v8 which uses a new framing format and expanded command id field from 8 bits to 16 bits. They also mention in the video at this EFR32 Mighty Gecko Series 2 dongle will ship with firmware config for 115200 bit rate speed by default so might have to change flow control configuration in OpenHAB Zigbee Bindings?
I have asked ITead via e-mail and been told that their design phase is completed and got the information ITead will initially only sell this Zigbee 3.0 Dongle without an external antenna (no SMA-connector or IPEX connector, so a built-in circuit board antenna only) and without a plastic-case as an enclosure (same as how they sell their CC2531 dongle today). I was also told that this new dongle will use the exact same Silabs SKU for the EFR32MG21 chip that is used on the board inside their Sonoff ZBBridge Zigbee Bridge (which can use as an alternative Zigbee to WiFi bridge if flashed with Tasmota and other Zigbee coordinator firmware).
I have no idea if they started production run or when it will available for purchase, however, my guess is that it will be sold at a relatively low price from their China store considering that their existing Zigbee Home Automation 1.2 dongle cost $3.99 and their Sonoff ZBBridge cost $16.90 in their China store.
Tip! Ember USB Zigbee adapters/dongles/sticks like these are highly recommended over using a remotely connected Ember module using a serial-to-ip bridge / serial forwarding server like ser2net.
FYI! Basically the serial protocol API for EmberZNet Zigbee coordinator application running on the Silicon Labs SoC/MCU does not deal well with unexpected loss of communication caused by network drops. The reason Ember remote bridges over serial-to-IP proxy server is not recommended is that clients using the EZSP serial protocol requires a robust connection between the EmberZNet Zigbee stack running on EFR32 MCU and the serial port of the Zigbee radio. With solutions such as ITEAD Sonoff ZBBridge or a Ser2Net serial proxy connection over a WiFi network it is expected to see
NCP entered failed state. Requesting APP controller restart in the logs. This is a normal part of the operation and indicates there was a drop in communication which caused packet loss to occurred between the zigpy radio library and the Zigbee radio. The use of serial network proxies/bridges/servers over WiFi is therefore not recommended when wanting a stable Zigbee environment with Silicon Labs Ember based Zigbee radios. The developers of the bellows radio library for the zigpy project has more information about this if needed.
Updated thread with price + links and some new information from ITead after the product was released.
Older and newer firmware as linked to by ITead:
Elelabs EZSP Firmware Upgrade Utility can be used to flash the firmware to a newer or older version:
This firmware upgrade tool has also been packaged by walthowd in a docker image:
Note! As you can see from the pictures the radio chip and the crystal does circuit does not have a EMF shielding (metal plate cover) which means that this board will be very sensitive with its current hardware design will have very high receive sensitivity to electromagnetic interference (EMI) / radio-frequency interference (RMI). This means that it will be extra important to keep it away from any other electronic devices or appliances that may generate an electromagnetic field (EMF or EM Field) or send our interfering radio signals. That includes the computer that you run your home automation application software on as well as any devices such as for example external harddrives or storage devices, power-supplies, etc., and of course any Wi-Fi access points or routers nearby. It also means that the dongle in its current hardware revision is unlikley to ever pass FCC certification. If adding electromagnetic shielding to your other devices/appliances is not possible then one workaround is to use the dongle with a long USB extension cable to get it away as far as possible from any sources of electromagnetic interferances.
PS: Also sad ITead didn’t add SMA or IPEX connector + external antenna or used ceramic chip antenna (new dongles with only integrated antenna should use a ceramic antenna, not just PCB trace antenna):