I did a workshop on "Simple IOT" at the Balccon2k17 in Novi Sad, now at its fifth edition. 

The participants received tens of kits to assemble (including some soldering) their "Simple IOT" devices, a cube like unit that runs on battery, measures temperature and sends all data online via Wifi. The workshop went great, and at the end we got several units up and running, talking to the server to report remote temperature readings.

More on this on the blog:  https://www.uradmonitor.com/balccon2k17

If interested in building yours, you can find all hardware and software details on Github: https://github.com/radhoo/SimpleIOT