Nick Tucker's AJAOne Is an Open, Arduino-Compatible, ESP32-Based MQTT Sensor Hub for Your Home
Released under the MIT license, the ESP32-powered AJAOne has eight digital IOs alongside UART, SPI, 1-Wire, and I2C buses.
Maker Nick Tucker has launched an open source, Arduino-compatible sensor hub designed to quickly build a home automation system controlled using the Message Queuing Telemetry Transport (MQTT) standard: AJAOne.
Built around the Espressif ESP32, the AJAOne aims to make integrating various types of hardware into a home automation system as simple as possible. "The AJAOne is a sensor hub that connects to your Wi-Fi," Tucker explains, "and natively supports 8 digital IO ports that can be used to read dry switches or provide an output to drive a relay."
"It has pin headers for a UART, SPI, 1-Wire bus and I2C as well as a STEMMA and a STEMMA-QT port. The STEMMA connectors provide the means to interface with devices from Adafruit and SparkFun."
While the AJAOne has no on-board sensors of its own, it comes pre-programmed with support for a range of add-on hardware: The 1-Wire bus is ready for DS18B20 temperature sensors, it supports BME and BMP280 temperature, humidity and pressure sensors, the BH1750 light sensor, SSD1306-based OLED display panels, and the MFRC522 radio-frequency ID (RFID) card reader.
"Using the AJAOne and Node-Red along with products like Home Assistant it becomes very easy to see the status of doors, windows, temperature, humidity, pressure and light all over your house," Tucker writes. "Additional functionality or enhancements can easily be added via the Arduino IDE with the ESP32 added to the board manager."
The AJAOne is now available on Tucker's Tindie store, priced at $29.99; documentation and source code can be found on the project's GitHub repository under the permissive MIT license.
