www.raspberrypi-spy.co.uk/2015/06/basic-temperature-logging-to-the-internet-with-raspberry-pi/
tutorials-raspberrypi.de/raspberry-pi-temperatur-mittels-sensor-messen/
learn.adafruit.com/raspberry-pi-analog-to-digital-converters/mcp3008
www.cl.cam.ac.uk/projects/raspberrypi/tutorials/temperature/
bluetooth enable
askubuntu.com/questions/787023/bluetooth-not-working-on-ubuntu-16-04-lts
* sudo nano /etc/bluetooth/main.conf
* Change #AutoEnable=false to AutoEnable=true (at the bottom of the file, by default)
* systemctl restart bluetooth