Instrument Navigation: Integrating Video and HUD
Use video and HUD together on large screens, and HUD alone on small screens unable to mirror. Learn how to handle and validate both paths.
Large screens: navigation video and HUD together
Large-screen instruments normally support both navigation video and HUD. Video shows the full navigation view rendered by the phone. HUD supplies turns, road names and distances for the manufacturer’s own UI. The paths serve different purposes; integrating video does not remove the need for HUD.
The terminal runs FreeRTOS. The APP handles maps and routing, the SDK handles communication, and the manufacturer connects wireless, decoding and display drivers.
Handle both paths
- Navigation video: receive compressed video over Wi-Fi, decode it and display it.
- HUD: receive structured turns and distances over BLE and keep instrument prompts updated. HUD does not include a base map.
Continue handling HUD events while video is active. Run slow decoding in a separate task so turn updates do not wait for it. Manufacturers choose the layout; supporting both features does not require overlaying both views.
Stopping video does not mean navigation has ended. Keep valid HUD data when only video stops. Clear the appropriate content on navigation end, disconnection or prompt expiry.
HUD alone when a small screen cannot mirror
When a screen is too small to show navigation video, use HUD alone for clear directions, road names and distances, and disable video capabilities. These instruments do not need the navigation-video Wi-Fi receive and decode path.
Use actual readability and display capability rather than a fixed size threshold. Large screens that can show navigation video should still integrate video and HUD together.
Verify each path, then both together
For large screens, first verify HUD events and video frames separately. Then run both: the map should remain smooth, turn updates timely, and repeated navigation starts and ends should leave no stale prompts or frames.
For small screens, confirm video is disabled and HUD remains readable. Old directions must clear when navigation ends or data expires. Test reconnection and navigation restart on target phones and the actual FreeRTOS board for both configurations.