Testing 9 external antennas with CC2531 ZigBee coordinator - NotEnoughTech
Alternative flashing methods | Zigbee2MQTT
China Cc2531 Cc2592 PA Zibgee USB Dongle Gateway Router - China Cc2531 Zigbee USB Dongle, Cc2531 Wireless Module
Wireless ZigBee CC2531 USB interface module dongle protocol analysis data packet capture development board border router green|Integrated Circuits| - AliExpress
ITEAD of Sonoff fame now sells a very inexpensive Zigbee USB dongle that should work out-of-the-box with Home Assistant ZHA integration and Zigbee2mqtt : r/homeassistant
CC2531 Zigbee Coordinator oder Router in Brandenburg - Kremmen | eBay Kleinanzeigen