I have adapted en existing integration to fit my CTC EcoHeat 400 series ground heating unit.
The solution is built on an ESP-12F mounted on a dual relay board.
I have included documentation for the CTC SMART mode feature, that can potentionally save the owner lots of money, with the electrical proces we have seen lately.
Hi, I have tried to adopt your project to run on a Wemos D1 Mini towards my EcoHeat 410, not getting any values, is there no need for a RS485 to serial adapter on the connector located on the CTC display?
EDIT
Never got the setup with the Wemos D1 Mini to work, lucky for me modbus TCP worked flawlessly using this https://github.com/knudsvik/home-assistant-config/blob/main/packages/ctc.yaml