Direct-to-Worker Industrial IoT Alerting: A TinyML and BLE Wearable Prototype with Local Event Logging

This record archives a preprint-style technical manuscript describing a laboratory-scale proof-of-concept system for direct-to-worker industrial IoT alerting. The prototype combines TinyML-based vibration-state classification, Bluetooth Low Energy state transmission, an ESP32-C3 wearable alert receiver, multimodal LED/vibration/buzzer feedback, local LittleFS event logging, and a CAD/3D-printed vibration testbed for repeatable data collection. The manuscript documents the problem framing, system architecture, dataset preparation, model evaluation, prototype implementation, limitations, author contributions, and solution-engineering relevance for industrial safety use cases.