RedQueen

Date: 2025/-
Programs: NodeRed | Arduino IDE | Mosquitto MQTT
Technologies: MQTT | ESP32 micro controller | Raspberry Pi | IoT | NodeRed

About the Project
RedQueen is a privately developed smart home system that provides a modular, scalable solution for monitoring and controlling environmental conditions. The core idea was to use freely available hardware and open source software to create a powerful and customizable platform that is suitable for both private living spaces and technical application environments. The architecture is based on a central Node-RED server on a Raspberry Pi, which communicates via MQTT with a large number of standardized sensor and actuator modules based on ESP32. The aim was to achieve simple expandability while minimizing the programming effort through reusable code components and module designs. RedQueen enables the recording of environmental data such as temperature, humidity and CO₂ content as well as the control of a wide range of consumers - from plant lamps to irrigation systems and household appliances - via an intuitive dashboard. The system is actively operated and continuously expanded.

Technical Appropach
RedQueen's entire system architecture is designed as a distributed IoT system. A Raspberry Pi takes over the central control and visualization using Node-RED and MQTT-Broker. Communication is completely wireless via Wi-Fi. The end devices consist of modular ESP32 microcontrollers, which are quipped with various sensors (DHT22, SCD40, soil moisture sensors, etc.) and actuators (relays, MOSFETs, LED drivers). A high degree of standardization has been achieved through uniform firmware templates in the Arduino IDE, which facilitates both maintenance and scaling. The Node-RED dashboard serves as a central user interface for realtime monitoring, manual control and automated processes (e.g. time- or threshold-controlled).
All data points and control processes are mapped via MQTT in a hierarchical topic structure and can be integrated into Home Assistant or external systems if required.

Retrospective
RedQueen was born out of the desire to create a fully controllable and locally operated smart home system that works independently of cloud services. The modular structure of the system has proven to be extremely robust and flexible during operation. Particularly noteworthy is the simple reproducibility of the sensor modules, which means that new rooms or areas of application can be developed quickly. Thanks to the complete in-house development of all components - from hardware layouts to firmware and control logic - in-depth knowledge in areas such as embedded systems, network communication and IoT automation has been built up. Future enhancements include voice control integration, energy consumption monitoring and better long-term data storage and analysis. RedQueen remains an active project and also serves as an experimental platform for new control and sensor technologies.