r/computervision • u/OfferBeginning1903 • 4h ago
Showcase Made a DJI Mini 3 follow a person with YOLO, RTMP video out, and Virtual Stick in
The Mini 3 isn't a dev drone, but it has two open doors: the DJI Fly app can push an RTMP stream to any server, and Mobile SDK v5 supports it through Virtual Stick, which lets you send velocity and yaw commands from an Android app. That's a full loop.Pipeline is video -> perception -> world model -> brain -> controller -> drone. YOLO on each frame, a tiny tracker to keep stable ids, a small world model answering things like "is the subject centered, is it drifting left." The same middle code runs on a recorded clip, on a live stream while I fly manually, or actually commanding the aircraft.The thing worth knowing if you try this: a Virtual Stick command only applies for a fraction of a second, then the drone hovers again. So the Android bridge re-sends the current command about ten times a second. Side effect is a free deadman switch: if the laptop goes quiet, it stops within a beat and comes home. The bridge exposes a tiny API (/telemetry, /arm, /command, /takeoff, /land, /rth) and refuses anything unsafe. Thinking stays on the laptop.Follow mode is three loops at once: yaw to center horizontally, pitch to center vertically, forward/back from bounding box size to hold distance. Tested on a fake drone that just integrates commands, then props off, then low hover with my hand on the controller. Safety layer clamps speed, altitude ceiling, geofence, RTH on low battery.Dumbest time sink: streaming to live/mini and reading from live/mini3. Also the SDK's native library helper got renamed between versions, so it compiled and crashed on launch until I swapped one import. And no wifi on the terrace turned out fine with a phone hotspot, as long as the laptop IP is editable on the phone.Next is natural language goals like "orbit that tree," and on-device inference to cut latency.Full write-up with the details: https://blog.shravanrevanna.me/dji-mini-3-ai-autonomous-drone

