Those who have been tinkering with Home Automation and Home Assistant longer are most likely familiar with the Conbee II – A universal USB Zigbee Gateway developed by Phoscon Dresden Elektronik.
This stick was released more than 5 years ago and was the main coordinator in many smart home Zigbee networks, including mine. As most things tech, It has become outdated and subsequently replaced with more current and better coordinators – like the Sonoff ZBDongle-E or ZigStar UZG-01.
The Conbee II was superseded yesterday with the official release of the Conbee III, a completely new and universal Zigbee gateway based on the SiLabs EFR32MG21 SoC. It’s available only on Amazon Germany for now and costs €39.95.
Conbee III vs Conbee II
The first thing most will wonder about is What is the difference between the two? How is the Conbee III better than the II? Here’s a side by side technical specification comparison of both:
Conbee II
- Model: Conbee II
- Microcontroller: ATSAMR21B18 ARM® Cortex®-M0+
- Rated voltage: DC 5.0 V
- Transmission power: max. 10 mW
- Signal range: 200 m in free line of sight
- Radio frequency: 2.4 GHz
- Radio standard:Â IEEE 820.15.4 / Zigbee 3.0
- Flash memory: 256 kByte
- Storage temperature: -20 °C to 55 °C
- Operating temperature: -20 °C to 55 °C
- Operating systems:
- Microsoft Windows 7 / 10, Ubuntu, Raspbian, Docker
- Dimensions: 60 mm × 18 mm × 9 mm
- SKU: 600107
- EAN: 4260350821328
Conbee III
- Model: Conbee III
- Microcontroller: EFR32MG21 ARM® Cortex®-M33
- Rated voltage: DC 5.0 V
- Transmission power: max. 10 mW
- Signal range: 200 m in free line of sight
- Radio frequency: 2.4 GHz
- Radio standard:Â IEEE 820.15.4 / Zigbee 3.0
- Flash memory: 1024 kByte
- Storage temperature: -20 °C to 55 °C
- Operating temperature: -20 °C to 55 °C
- Operating systems:
- Microsoft Windows 7 / 10 / 11, Ubuntu, Raspberry Pi OS / Raspbian, Docker
- Dimensions: 60 mm × 18 mm × 9 mm
- SKU: 600115
- EAN: 4260350821366
While on paper it might not seem like much, the Conbee II is based on the ATSAMR21B18 [Datasheet] module by Microchip, which a weak and dated connectivity module. The EFR32MG21 [Datasheet] in the Conbee III on the other hand, is developed by SiLabs and supports more devices in a direct connection.
The Conbee III ships with firmware that supports Zigbee 3.0 and Zigbee Green Power devices. OpenThread Border Router firmware will be available as a tech preview soon, per the company. BLE support for onboarding Thread (Matter) devices should also ship with this new firmware.
Since the Conbee III is based on the EFR32MG21, the same module used in the ZBDongle-E and SkyConnect, it can be flashed with Multi-PAN firmware supporting both Zigbee and Thread networks down the line. You can already do this with these two, follow the guide here.
Should you upgrade?
I’m all for the “don’t fix what ain’t broke” viewpoint, so I believe this also applies here. If you have the Conbee II and everything works as it should, there is no reason to upgrade right now.
Be mindful that official support for the Conbee II has stopped and you are limited by the number of devices you can add to this coordinator. In a direct connection, it can support only 24 devices. You can extend this limit with routers in an ideal setup, but this is easier said than done.
The Conbee III can handle up to 200 devices in a direct connection and extend up to 500-600 with routers and proper setup. As the EFR32MG21 has more RAM, the III will not struggle like the II in the case of a larger network.
In any case, you should consider adding dedicated Zigbee signal repeaters and boost network stability. Alternatively, check out this list of the Best Zigbee Coordinators for Home Assistant.
Pricing and Availability
The Conbee III is available on Amazon Germany only for the time being and costs €39.95. I expect it to popup on other global stores in the upcoming months.
Related posts:
How would ConBee III compare to SONOFF Zigbee 3.0 USB Dongle Plus? Can ConBee’s lack of external antenna be a disadvantage?
As far as I know, using an IPEX antenna (external) makes little to no difference in SiLabs EFR32MG21-based coordinators.
However, we might have to wait for the Conbee III real world tests to know how the two compare.
Info on IPEX: Tests done by developer of ZigStar
Strange that they did not go with the newer EFR32MG22 or EFR32MG24 which have even more RAM
Is it better than SkyConnect? How do you compare them?
They have the same chip (EFR32MG21), so they have the same hardware capabilities.
But in practice, a lot of it depends on the firmware. I cant know until I test the Conbee III.
For now, I would not buy it to replace the SkyConnect or the ZBDongle-P/E.
Finally someone not just doing a copy n paste job of what the manufacturer states on their web site…
Thanks for pointing out details and differences!
Cheers!
You are welcome man, appreciate the feedback.
I do not think conbee 2 is limited to 24 devices. I have 73 devices in the network with Cobee2 both direct and via routers (I can swear that more than 24 are in direct mode).
until now work vey well