.... rummaging in the drawer of old electronic components, I found one temperature / umidity sensor, one display and an arduino promini... so... what to do with these things ?
I did not want to leave them in the drawer, then I have attached them to the tree :)

I must add some schematics, arduino code and instructions... I do this ASAP :)

the vertical tube is aluminum D8mm and the other 3 orizzontal are D.6mm (found in brico-center shop). Can be cutted at the desired lenght :).

I posted this, in particular as an idea, thet can be adapted to any other type of electronics circuit / sensor etc.