I think I must have read almost every page on this site when I discovered it. I really loved this idea. For ages I've wanted to monitor and interact with my surroundings via some home automation solution, but all the commercial solutions are really expensive and limited. MySenors and OpenHAB really give me the customisation I want.
The only thing missing was putting everything together. I'm working on that. But first I needed to create my sensors, as small/cheap as possible and battery powered.
Here's my first pass at building the temperature sensor, in a 3D printed box which also houses the battery compartment.
The circuit board (Single Sides Etch) slides in on groves in the walls. I added the battery monitoring to the Arduino as I really need to know if/when the batteries are going flat. That's all pushed back to openHAB which I can then create a rule to watch for battery low, however so far the batteries seem that they will last for ever!
The contacts on the battery box are small flat metal. Aluminium between the batteries, and Copper for the terminals. I used copper as I could more easily solder to it.
Making it very easy to assemble.