I’ve made a small breakthrough this evening and can see and control the temperature in multiple rooms
However, I worry that every system is different so it may be tricky to implement so it is compatible with everybody’s setup.The JSON has changed since I added a new TRV so there is now a list of items where there used to be a single text line. Ideally I’d like to compare the JSON from a few setups to see if it has changed because of a firmware update or because the heating devices are different. @Chris_Evans Are you able to PM me your JSON response from /domain/data. You can redact anything such as serial numbers, etc.
I’ve also noticed that the TRVs don’t report on humidity. The only way to get humidity is from the RoomStat (the little white box) device rather than at a room level. This is a bit of a shame as it’s useful to have to triggering extractor fans in bathrooms.
I’ll finish on some good news. There is a QR code with a serial number printed inside each device. This matches the internal Serial Number stored in the JSON for each device and means it will be easy to add a device to the things file for battery level monitoring. I’ve come up with a (terrible) schema of how the system sits together.
Oh, and I found a WindowState value. IIRC the Honeywell system has a way of telling when a window has been opened due to a sudden drop in temperature. This could be similar.