Design and Implementation of an IoT-Based Student Bus Tracking System Using ESP32, MQTT and FastAPI

Students who depend on college buses often lack timely information about where the bus is and when it reaches their stop.This paper presents an IoT-based student bus-tracking system that com-bines an ESP32 GPS unit, MQTT communication, a FastAPI backend and a browser-based map.The backend validates incoming telemetry, maintains each bus's movement state, and stores positions and alerts in Supabase.Live positions and alerts are pushed over WebSockets to open browser clients, while Firebase Cloud Messaging (FCM) delivers background notifications to the devices of users subscribed to a bus; Supabase authentication handles sign-in.The alert engine generates eventbased alerts for stop proximity, route deviation, trip milestones and loss of tracking data, and a GPS simulator exercises this logic.The reported evaluation comprises 24 automated unit tests, simulator runs, and a walking trial with the ESP32/GPS unit.The simulator runs ex-posed a missed-arrival case in which a bus crossed a stop between two consecutive location updates, and a segment-based proximity check was introduced to correct it.The paper describes the architecture, vali-dation rules and deployment considerations of a practical student bus-tracking prototype.