Desenvolvimento de uma plataforma IoT para monitoramento de dióxido de carbono e amônia

Abstract

This work presents the development, implementation, and validation of an Internet of Things (IoT)-based platform for the continuous, real-time monitoring of carbon dioxide (CO₂) and ammonia (NH₃) concentrations, with potential applications in container-based vertical farming systems. The proposed architecture employs an ESP32 microcontroller as the data acquisition and transmission node and a Raspberry Pi 3B as the local server, responsible for data management through the MQTT protocol. Node-RED was used for data processing, the development of real-time visualization dashboards, and the local storage of measurement records in CSV files. To validate the system, an experimental methodology was developed based on the controlled release of ammonia from ammonium hydroxide solutions with concentrations of 0.077, 0.153, and 0.306 mol·L⁻¹, enabling the evaluation of the platform's dynamic response during the mass transfer process between the liquid and gas phases. The experimental data were fitted using a first-order dynamic model, allowing the estimation of the apparent parameters associated with NH₃ release dynamics. The correlation coefficients obtained (R = 0.9808, 0.9831, and 0.9565) indicated excellent agreement between the model and the experimental data, demonstrating the high sensitivity of the proposed platform in tracking the temporal evolution of gas concentration. The results also showed consistent performance of the non-dispersive infrared (NDIR) sensor for CO₂ measurements, exhibiting stability and accuracy throughout the experiments. The developed platform demonstrated high reliability in data acquisition, transmission, storage, and visualization, highlighting its potential for applications in container-based plant cultivation systems and other scenarios requiring continuous environmental monitoring.