This thesis explores the design and implementation of a real-time monitoring system for dissolvedoxygen (DO) levels in aquatic environments, with the goal of enhancing environmental research anddata analysis. The primary focus is on developing a proof of concept using a single ESP32microcontroller paired with a DO sensor, while laying the groundwork for future scalability toincorporate multiple sensors that can measure various water quality parameters.

The system architecture is designed to facilitate the autonomous operation of sensors, enabling datacollection and transmission through a wireless sensor network (WSN) using long-rangecommunication protocols such as LoRaWAN, LTE-M, and NB-IoT.

A prototype system is developed to test the design and functionality, ensuring that the architecturecan effectively collect, transmit, and visualize data in real-time. The findings indicate that theproposed system not only meets the requirements for accurate DO measurement but alsodemonstrates the feasibility of expanding to a multi-sensor setup for comprehensive environmentalmonitoring. This research contributes to the advancement of effective environmental monitoringsystems.