Buzzer

🟢 Start — zero knowledge, plain words. 🟡 Hands-on — building or buying, specifics and tradeoffs. 🔴 Specialist — the physics and math behind it.

🟢 Start. A small beeper, a big deal: a drone in tall grass is invisible from two meters away. Self-powered versions (~100 dB with their own cell) keep beeping even when the main pack ejects on impact — and it ejects often.

🟡 Hands-on. A plain buzzer wires to the FC's BZ+/BZ− pads and gets behaviors assigned in firmware: beep on signal loss, beep on demand from a switch (searching), low-voltage warnings. Mount a self-powered one so its button stays reachable after you find the drone — otherwise it will donate its full 30 minutes of glory to the entire forest. Complements: LED strips (dusk searches) and a cheap BLE tracker tucked in the frame.

🔴 Specialist. The best "buzzer" is sometimes digital: record goggle DVR with GPS coordinates in the OSD — the last frame before signal loss is a ready-made waypoint for your phone. The specialist's recovery chain is layered: rescue mode (it comes back by itself) → DVR coordinates (you know where it lies) → buzzer/LED (you hear and see it up close). Three independent layers, three different failure modes.

⚠️ Common mistakes: no buzzer over meadows — the most expensive $10 saving in this hobby.

🖼️ Photos: your own TPU mount with a naked GoPro; a DVR frame with coordinates visible in the OSD.