BatBox - DIY IoT Wi-Fi Boiler Controller in Java with Spring Boot and Pi4J
This is a talk that I gave at the West Midlands Java User Group (WM-JUG) at Connect Group's BHX office in Trinity Park, Birmingham, on Tuesday 27th September 2016, on my BatBox Boiler Controller - my answer to the Nest and Hive thermostats - but built using the Raspberry Pi 3 and Open Source software, including Java, Spring Boot, and Pi4J.
Pi4J is an open source Java library which gives access to the Raspberry Pi's GPIO (general purpose input/output) interface - allowing sensors to be read, and electronics to be switched on and off. One Raspberry Pi 3 will act as a room thermostat in the lounge, reading temperature and humidity. Another Raspberry Pi 3 will act as a boiler controller in the kitchen using a relay board to switch the boiler on and off. Control is via simple HTTP endpoints over Wi-Fi, to read the temperature/humidity in JSON format and switch the boiler on and off - thus giving you complete control of what timer/thermostat control software you want to put in between to give you a feature-rich central heating control system, without being locked into a particular vendor.