The past months I’ve been working on creating my own smart thermostat. More info is available at http://www.janwagemakers.be/jekyll/portfolio/smartthermostat.html and https://gitlab.com/jan.wagemakers/thermostat/.
A demo version to show the current web interface of the thermostat is available at http://janw.mooo.com:24388. Note that in this demo version it’s not possible to change the database (“rules”, “users”, “configuration”). The current temperature it shows is just a random value. It’s just there to show the interface.