The Raspberry Pi is a tremendous device for controlling things around the house, but for many applications it is overkill. A platform based on a microcontroller is then more appropriate. The ESP8266 is a popular platform for IoT applications that connect via WiFi. It is Arduino based, you can find many cheap ESP8266 boards and you have access to various analogue and digital pins.
In this book Hans Henrik Skovgaard builds several IoT devices based on the Wemos D1 Mini Pro board: a WiFi controlled lamp, a door lock guard, an energy sensor and a fridge controller. This doesn't look like much, but the construction of each of these devices is comprehensively explained, from the hardware schematic and mechanical construction to the software. Because of the depth of the author's explanations, you will learn so much that after reading this book you will be able to build other IoT devices for around the home.
The book does have a somewhat slow start: you will be nearly halfway before you get to build anything. That is because the author gives quite a bit of attention to the components he uses, and the installation of the tools 'emoncms' and 'Mosquitto' on a Raspberry Pi. The first is used as a vizualisation program and the second for passing the data from his IoT devices to the Raspberry Pi. This is all interesting information, but if you are impatiently waiting for the construction of devices then it is perhaps better to delay reading these chapters until the end. However, a very important chapter for hobbyists is the one dealing with selecting a suitable antenna.
A disadvantage of the book is that for much basic information a reference is given to online sources. Also, the Python code is still written in Python 2.7, which is no longer supported since the beginning of this year. On the other hand, the book is richly illustrated with photos, screen shots, electronic schematics, graphs, architecture diagrams and even flowcharts for the software. All this explains the constructions of the author very well, and after his book you will have a more than sufficient understanding of how to build your own IoT devices.
Author: Hans Henrik Skovgaard
Publisher: Elektor International Media
Price: € 34.95
Further information and ordering: https://www.elektor.com/iot-home-hacks-with-esp8266