Digital Tour Guide System

An onboard digital tour guide built for an electric vehicle prototype. As the vehicle moves along its route, passengers receive location-aware narration and visuals on synchronized displays.

I built the system that ties vehicle position to content: GPS tracking feeding geofence triggers, which in turn drive what every screen shows at any given moment.

A tour that runs on physical movement has constraints a normal web app does not. Content has to fire at the right moment on the route, not a few seconds late, and every screen has to be showing the same thing at the same time.

It also has to hold up in a moving vehicle, where GPS accuracy drifts and connectivity is intermittent. Losing signal mid-route cannot mean losing the tour.

The system came together as a handful of connected pieces:

• Real-time GPS position tracking
• Geofence definition with enter and exit triggers
• Synchronized playback across multiple displays
• Route and point-of-interest content management
• A live operator view of vehicle position and tour state
• Offline-tolerant state handling for connectivity gaps

Position data flowed from the vehicle into geofence evaluation, which advanced tour state, which the displays subscribed to — one source of truth from GPS fix to rendered screen.

The synchronization problem shaped the architecture. Rather than letting each display track its own position and decide independently, I made one process the clock and the screens subscribers to it, so they cannot drift apart.

Geofences needed hysteresis. A raw enter/exit test flaps continuously when the vehicle idles on a boundary or GPS accuracy wobbles, which would fire the same trigger repeatedly. Separating the enter and exit thresholds made triggers fire once and stay fired.

The system delivered a synchronized, location-triggered tour experience running on the vehicle prototype.

Building it meant working much closer to hardware and physical state than a typical web project — real-time position, multi-device synchronization, and graceful degradation when the network is not there.