I’ve written a blog post after finally getting a bluetooth based sensor into openhab. It’s based on an idea I had in August - iBeacons for room based temperature sensors?
Blog is here with some detail. The code I’ll post on github.
Nice, something like this would have been most definetely a better alternative to my netatmo devices. Somehow I still have a unhappy feeling about sending all my data to some strange company just so I can pull them back again into my OH.
It is amazingly “interesting” how much you can read about my living habits from the CO2 and humidity data 
Ah yeah, definitely happier to keep that sort of data local.
And while my post does look like an ad for blue maestro, the concepts are transportable across devices - as long as you can get access to the advertising packet structure.