The Rationale: Why I Need Home Automation
I have a large home improvement project going on: I am building a swimming pool. Of course, my kids are all excited over this! The problem I had to solve is, that I had to find a way to control the pool technology, which is located in a little shed behind my house. Of course I do not want to walk all the way from the pool around the house to the shed just to turn on the pool lights. So I bought a couple of DECT controllable power sockets, which control the heat pump and the lights. With this solution, I was able to control the lights with the swipe of single finger on my smart phone, without walking a single step. My craftmen, who built the pool, were truely impressed 
I invested 100 € (~ 120 $) for two DECT controllable power sockets plus 10 € (~ 12 $) for 50 m (~ 150 feet) of electric cable. I didn’t have to go through the trobule of breaking up my walls for placing electric switches and I got the luxury of remotly controlling my pool’s electric from literally every place on earth. I am returning early from my vacation and I want the water to become warm by the time I get back home? No problem, I simply turn on the heat pump before I leave the hotel. Any conventional solution would have been by far more expensive and would not give me the luxury I am expriencing now.
Why I Switched to openHAB
So far, I was able, to control the pool via the app of my WiFi router. However, I hungered for more. I learned quickly through a research, that openHAB provided many bindings to devices I already owned, most notably iPhones / iPads, the AVM Fritz!Box and a KODI home cinema server. So I decided to download openhabian for an outdated raspberry, that was sitting on my desk for quite some time and quickly built an user interface including the locations of my smart phones / tablets, a weather forecast, and of course control over my newly built pool. I also learned, that my DECT power sockets have integrated temperature sensors, so I built a graph to monitor the temperature in my shed over time. This might become handy in winter, because I want to remove certain goods from my shed before they are damaged by frost.
While studying this graph, I learned several interesting facts:
- every afternoon I see an unexpected rise in temperature. As the shed is located in the northwest of my house, it remains within my houses shadow all day long until roughly 5 p.m. Then the sun shines directly on the shed, resulting in an increase in temperature.
- on Thursday 24th my WiFi router stalled for roughly 10 hours. I had to restart it.
Maybe, this will become the starting point for a big data analysis, e.g. deep learning algorithms or the like. We will see, as time goes by.
How I Continued
I also learned from a friend and collegue of mine, that you can easily build your own IoT network with an ESP 8266 (a 32 bit computer with integrated WiFi for less than 2 €) using Homie. I attached a Bosh BME680 via I²C to it and built a quick prototype of an indoor climate measurement device, monitoring air temperature, humidity, air pressure as well as the indoor air quality indoex (IAQ). Right now it is still a prototype and my wive will never allow this sitting in our living room, but it is good enough to give a rough expression of what I did:
By the time of this writing I am missing a bunch of components, which I ordered from China and they are still on their way. Therefore I am using a 5 volt power supply for my bread board (top right). It will soon be replaced by a LiPo battery. The circuitry to the very left is a voltage regulator stabilziing roughly any voltage between 3 and 12 volts to the 3.3 volts required by the system-on-chip, which recides on the circuit board attached to the broadband cable. The Bosch multisensor is the green circuit board in the center section. Hidden below the USB cable resides an RS232 interface for flashing the firmware. The data is evaluated by openHAB via the MQTT binding.
What I Will Do Next
Of course I will do the obvious and replace the breadboard with a printed circuit board and embedd it in a 3D-printed compartment. Also, with time passing by, I found many interesting do-it-yourself projects on the web, including a Z-Wave pool thermometer. So, guess what: I purchased a Z-Wave USB dongle for my raspberry pi and I am simple overwhelmed by the number of Z-Wave device available. How neat will this be: check the iPhone when still lying in bed, check the water temperature and decide whether to go for a little swim first or get the morning coffee first. 
Life is a project!