I have an OpenTherm gateway like this one:
https://www.nodo-shop.nl/nl/opentherm-gateway/188-opentherm-gateway.html
I have been using it with a NodeMCU running a serial server, using the ‘opentherm_gw’ component, which wasn’t very fancy as I had a constant serial (telnet) session open, which didn’t reconnect if a network failure occurred (even made HomeAssistant completely unresponsive after that).
Anyways, I have been searching for ways to have the NodeMCU (ESP) translate the OpenTherm data and publish it directly via MQTT. Nobody ever seen to have made such a thing and I am no expert writing C, so I resorted to this piece of Python script, running on a RPi:
https://www.phiax.nl/2018/02/snippet-opentherm-gateway-for-home-assistant/
It works great! Though, I find a Pi in between a bit redundant. Few issues I encounter and as I couldn’t find any documentation on the climate otgw component, I would like to ask you guys:
- The state is always off, nothing like heating or idle, as with the opentherm_gw component
- The sensors (manually created) have a precision of 0.01, I would prefer 0.5 or 0.1
- Changing the temperature is in steps of 1 full degrees, no way to set 19.5C for instance
Hope you can help me out on some attributes I can set or even documentation about this, or if you know a project of someone already attempting to use the NodeMCU to publish directly the translated OT to MQTT.
Thanks!