Low Voltage or battery powered zigbee relay?

[ritchierich]

What about an ESP8266 and Hubduino?

[Release] HubDuino v1.1.9 - Hubitat to Arduino / ESP8266 / ESP32 / ThingShield Integration (ST_Anything)

Announcing the release of HubDuino v1.1.7 (aka ST_Anything for former ST users) [UPDATE 1.1.9] This is a minor release to improve support for the latest ESP8266 and ESP32 Arduino IDE Board Support Packages. [UPDATE 1.1.7] This is a significant update to the Parent Drivers. Changes include: MAC Address no longer required when setting up a Parent Device. Only the IP Address/Port is required to help simplify initial startup. This also means that the micro-controller can be replaced with di…

SmartThings used to make an Arduino Zigbee shield but they stopped making it.