Design and Implementation of a Zone-Based BLE Indoor Localization System Using ESP32

Indoor localization is now an important part of intelligent environments, including smart buildings, retail spaces, hospitals, and industrial spaces. Bluetooth Low Energy (BLE) has become a potential technology in indoor positioning with low power consumption and ubiquitous nature. Nevertheless, traditional RSSI-based BLE localization schemes, such as fingerprinting and trilateration, usually experience multipath fading, environmental non-uniformity, calibration cost, and complexity of computation. The current paper describes the experimental validation of the design of a zone-based, calibration-free BLE indoor localization system with complete implementation on a low-power ESP32. Rather than calculating exact coordinates, the proposed method does the similar task of classifying zones proximity-wise by the use of lightweight sliding-window RSSI filtering and hysteresis-based zone stabilization. Signal processing and localization decisions are run directly on the embedded device without cloud dependency. Experimental analysis in a real indoor setting illustrates that the accuracy of zone detection of RSSI filtering increases on average, between 74% unfiltered and 91% filtered, at low computational complexity and infrastructure. The proposed architecture offers a scalable and efficient resource-based solution that can be used in real-life usage of proximity-sensitive types of applications.