The sensor network consist of various Arduino-based nodes. Both AVR and ESP8622-based, using 433Mhz modules or WiFi in the later case.
I also have made a mobile micro-dashboard (not Splunk related) public for accessing when I'm not at home. It's a simple JQuery-made thing that fetches a JSON file held in memory, that contains the latest values sent via the MQTT network. If a value is older than 1 hour a red warning triangle will show to indicate that the value might not be updated.
Sorry for the Swedish. It says Kitchen, Fridge, Freezer, Balcony and Basement.