Cheapest way to get accurate room temps (multizone)

Hi all.

I messed about with smartthings a while ago in the search for a decent hot tub temp measuring/heating system which winded up working just wonderfully with a fibaro ubs module and a handful of dsxxx sensors.

Temp updates were frequent and accurate.

I’m messing around with some smart trvs and a z wave boiler switch now to give multizone heating. At the moment this relies on the temperature readinga from the trvs, but as you can imagine this isn’t quite an accurate reflection of the temperature of the room.

So… At the moment I’m thinking of doing something like hooking up 7 dsxxx probes spread throughout the house and using those to control when to fire up the heating etc. But from memory, the fibaro only takes 4 of these. And the fibaro is about 50 quid.

Don’t fancy spending 2 x 50 quid plus probes to achieve this… Can anyone suggest a better way? In total I’ll end up having around 11 temp probes around the house… Is there’s a better way, and I can have the whole lot connected to one module of some sort that would be awesome. I’m thinking it’s possibly going to be raspberry related… Who knows! Over to you! Cheers!!