I have a friend who a few months wanted to automate/remote control a water pump at his cabin and monitor his solar system and batteries. He has internet connectivity there but otherwise is off the grid. So I thought okay, raspberry pi, arduino with an Ethernet shield and some extra electronics, and then use dataplicity to remote connect. It's not straightforward with his internet setup to initiate a connection from the outside world. But he wasn't crazy about controlling the thing with a command line and really wanted a web interface. After some searching around I ended up using Home Assistant. We are still putting it all together but it's been very nice so far, like battery voltage graphs and sending/receiving data via MQTT is really pretty easy.