Port of ComfoAir protocol to ESPHome.io firmware originally by @wichers modified by @nyxnyx to be installed as external_components. Modified for the Zehnder WHR 950 by @tieskuh. With some cheap hardware found below, you can connect your Zehnder to HomeAssistant.
This fork was modified to work with the first gen RS485 protocol for Zehnder WHR / ComfoAir CA-500 It is still a WIP so usage is fully at own risk.
Look at comfoair.yaml