Connectivity issues due to interference

Zigbee devices, including Home Assistant Connect ZBT-1, can't communicate reliably if they are too close to other electronics which cause interference. Especially USB 3.0 devices are known to interfere with the 2.4 GHz based protocols such as Zigbee or Thread.

The video below demonstrates this effect: when the stick is moved closely to a source of interference, the light switch and the light cannot communicate.

Technical note: Home Assistant Connect ZBT-1's IEEE 802.15.4 radio (like any Zigbee radio) uses a technique called CCA (Clear Channel Assessment). Before sending, the radio listens on the channel it wants to use. If there is traffic on the channel, it prevents the sender from becoming active. Traffic is not limited to the Zigbee protocol. There is also traffic from other protocols which use the same 2.4 GHz band, as well as electromagnetic interference from other devices.

For an in-depth description of the issue, refer to the white paper issued in 2012 by the Intel Corporation
USB 3.0* Radio Frequency Interference Impact on 2.4 GHz Wireless Devices

How to counter interference

In some cases, the extension cable delivered with Home Assistant Connect ZBT-1 is not enough to circumvent interference. In this case, try the following measures:

  1. Use a longer and/or a shielded extension cable.
  2. Make sure the Home Assistant Connect ZBT-1 is not near any of the following devices:
    • USB 3.0 devices or hubs
    • external SSDs or HDDs
    • 2.4 GHz WiFi devices, routers, or SBCs such as a Raspberry Pi