> ## Documentation Index > Fetch the complete documentation index at: https://stem-docs.intellectualpoint.com/llms.txt > Use this file to discover all available pages before exploring further. # Anatomy of your drone > Learn the name and job of every major part of your Echo Drone before you build it. ## Know your drone inside and out Before you build and fly, get to know the parts. Every component has a job, and knowing them makes building, flying, troubleshooting, and coding far easier. Labeled diagram of a quadcopter drone showing propellers, motors, prop guards, frame, battery, camera, LED, and optical-flow sensor ## Every part, pulled apart Sometimes it's easiest to understand a machine by taking it apart. Here's your Echo Drone "exploded" into its main pieces - stacked in the order they fit together. Exploded diagram of a quadcopter showing propellers, prop guards, motors, flight controller board, battery, camera, optical-flow sensor, and LED separated in layers ## The major parts Four spinning blades that create lift by throwing air downward. Your drone has two **A** (forward) and two **B** (reverse) propellers arranged in an alternating pattern. Four small electric motors, one at the end of each arm. Changing their speeds is how the drone rises, tilts, and turns. Circular rings around each propeller. They protect the blades - and your fingers and walls - during indoor flight and crashes. The central chassis that holds everything together and houses the flight controller (the drone's brain). A clip-in 3.7 V lithium battery that powers the motors and electronics. It provides 9-10 minutes of flight and recharges in about an hour. A front-facing 720p camera that streams live video over Wi-Fi. This is the camera you'll fly with in first-person view on Day 4. Shows the drone's status through different flash patterns - pairing, headless mode, low battery, and more. A downward-facing sensor that watches the ground to hold the drone's position steady when hovering indoors. ## The brain: the flight controller Hidden inside the body is the **flight controller** - a tiny computer that runs the show. Many times every second it repeats the same three-step loop: **sense** what's happening, **think** about what to change, and **act** by adjusting the motors. Diagram of the flight controller's sense-think-act loop using gyroscope, accelerometer, and optical-flow sensor to adjust four motors When you fly, you don't control motors directly - you tell the flight controller what you *want* (go forward, turn left), and it does the fast motor math for you. Later, your code will send it those same requests. ## The sensors that keep it steady The flight controller is only as smart as the sensors feeding it. Three tiny sensors - the same kind inside your phone - let your drone balance itself. Detects how fast the drone is tipping or spinning, so it can level out. Measures speeding up and slowing down, and which way is down. Watches the floor's texture to hold position instead of drifting. ## Reading the LED light Your drone talks to you through its **LED light**. Learning the flash patterns means you'll always know what it's doing - pairing, ready, or low on power. Chart of drone LED light states: fast blinking pairing, slow blinking ready, alternating headless mode, red blinking low battery, solid connected Point to each part on your own drone as the facilitator names it. Being able to find the battery, camera, LED, and prop guards quickly will speed up every activity this week. ## Quick quiz You tell the drone "go forward." Which part figures out how fast to spin each motor? Indoors with no GPS, which sensor keeps your drone from slowly drifting across the room? You can find and name the propellers, motors, prop guards, battery, camera, LED, and optical-flow sensor on your drone, explain what the flight controller does, and read the basic LED patterns.