Xu Jiwei's AirCube Is a Smart Air Quality Sensor with Domoticz, Home Assistant Connectivity
With a built-in IPS TFT or ePaper display and MQTT messaging support, the AirCube is a compact but function-packed smart home accessory.
Developer Xu Jiwei has designed a modular air quality monitor designed to display current and historical data on an on-board display while simultaneously reporting to Domoticz or Home Assistant: the open-hardware AirCube.
"I have always been concerned about the environmental status of my home," Xu explains, in translation, of the project's origins. "Many years ago, I used a universal board + ESP8266 + sensor to assemble a lot of air detection nodes at home to monitor PM2.5 concentration, carbon dioxide concentration, temperature, humidity, and other environments state. This upgrade is mainly to improve some problems encountered by old components such as [through-]hole board and ESP8266."
Not least among the reasons for the upgrade is the aesthetic appeal. Where the older Espressif ESP8266-based air quality monitors put their inner workings on display, housed on tiered transparent plastic sheets, the AirCube packs everything into an attractive 3D-printed box. The redesign also gave Xu a chance to standardize the components, improving consistency between nodes.
"[It's also] more powerful," Xu explains. "The original ESP8266 module has a small number of GPIOs [General Purpose Input/Output pins]. In the case of a large number of sensors, those GPIOs are not enough. This time it is replaced with a more advanced ESP32, which has more GPIOs and more powerful performance. And because there are more GPIOs, an additional screen can be added so that even without the help of Domoticz it can be used independently to view the current environmental data."
The finished AirCube design uses an ESP32-based NodeMCU-32S development board, a Bosch Sensortec BME280 temperature, humidity, and pressure sensor, a Plantower PMS5003 PM1.0, PM2.5, and PM10 particular matter sensor, a Winsen MH-Z19B carbon dioxide sensor, an a Rohm BH1750 light intensity sensor — plus a pair of capacitive touch buttons to drive the user interface.
Those building an AirCube are given the choice of two displays: a 1.54" color IPS TFT, which provides the ability to read the air quality measurements even in a fully darkened room, and a 1.54" ePaper display that is highly readable in direct sunlight and draws very little power but which is useless in the dark. For connectivity, ESPHome is used to connect each sensor node to Domoticz, Home Assistant, or any other server capable of receiving MQTT messages.
More information on the project is available on Xu's blog, while design files and source code can be found on GitHub under the permissive MIT license.