Private smart home: Structural monitoring and control with open-source technology

Abstract

In collaboration with a colleague from the department of construction in 2018, a temperature monitoring system was developed over a short time frame to log temperature for comparison of thermal performance for two otherwise identical buildings built to different building standards. The reliability of this implementation became the topic of a conference paper published in 2019 (Look, Holmes, & Birchmore). \

Each site used an ESP8266 WiFi development board, with DS81B20 digital temperature sensors, logging to a shared google spreadsheet.

These devices exhibited significant reliability issues once deployed. As time was limited, quick software interventions were implemented, and digital timers placed on the power supplies to reduce duration of lockups.

A new high-performance home completed in 2022 presents an ideal platform to make use of several open-source projects, which have gained popularity in the “smart home” market, to evaluate the comfort and efficiency the home. These provide alternatives for users seeking to avoid corporate owned cloud-based systems, the maturity of these solutions should offer greater reliability than the previous system.

Two of these solutions (ESPHome released in 2018 and Tasmota first introduced in 2017) are compatible with the same ESP8266 hardware used previously (indeed the exact same modules could be used to implement similar sensors and put into service for comparison), as well as more modern ESP32 based hardware. Another project, BTHome, has also become available for ESP32 utilising Bluetooth instead of Wifi, this solution has significantly reduced power consumption offers the potential to operate from batteries for extended periods (potentially months or even years).

These projects, and many closed systems have the capability to interact with a “Home Assistant” server, another open-source project which can run on a Raspberry Pi connected to the local network. Use of a local server removes the requirement for always-on internet access while capturing data. The presentation will detail the evaluation of different available solutions, as well as progress made to date implementing monitoring and where appropriate, control of in-home systems