What is an FPV drone? Everything you need to know

If you're getting started with FPV drones, this article is for you. FPV is short for First Person View, which means "first person view". In the context of drones, it refers to a system in which the operator controls the device by observing images transmitted directly from a camera mounted on board the drone. This image is transmitted in real time to special goggles worn by the pilot, allowing full immersion in the flight perspective. Below you will learn the most important terms and abbreviations of FPV.

FPV drone construction

The main component of the FPV drone is the frame, which connects all the elements together. Motors, flight controller, camera or battery are just, some of the parts that make up a drone.

We have described the various elements below:

Frame - Drone frame - usually made of carbon fiber (carbon), lightweight and very strong. The frames have different sizes (e.g. 5" - standard for freestyle, 3" - for cinewhoop). Frame shape affects aerodynamics, weight and component space.

Motors - Drone motors that allow you to control the drone in the air and accelerate it to very high speeds. There are 2 main parameters of motors - KV and size. KV tells us what voltage the drone is rated for, and what RPM it will have at a particular power supply (high voltage = low KV and low voltage = high kv).

For example, for a 5" drone on 6S batteries, the best KV will be at 1700-1900KV. The size determines for us the width of the stator (the inner stationary part of the engine) and the height. E.g. size 2207 means that the stator is 22mm in diameter and 7mm high.

Props / Propellers - Propellers with different diameters (e.g. 5", 3") and number of blades (2, 3, 4). More blades = more thrust and stability, but more load on engines. The type of propellers is chosen depending on the flight style and specifications of the drone.
Pitch is also important - it's a value expressed in inches (in) that determines how far the propeller would move forward in one full revolution if the propeller were moving through perfectly soft air (that is, without resistance or slippage).

Stack - A set of electronic boards (FC, ESC, VTX), mounted vertically in the turret, often using silicone sleeves (to eliminate vibration). Facilitates the installation and organization of cables. Popular sizes are:

• 20x20 mm
• 30.5x30.5 mm
• 16x16 mm (micro stacks)

Rechargeable battery (pack, battery) - Thanks to them, the drone receives power. Extremely important element, battery capacity, weight, number of cells, or dimensions are the parameters to pay attention to when choosing the.

Types of FPV drone frames and styles

Drones vary in weight, size and purpose. Those with a smaller build are usually better suited for aerobatics and flight style practice - mainly indoors. On the other hand, the larger drones have a better quality camera and are able to fly for up to kilometers. Below we describe the main four types of FPV drones:

Cinewhoop - Stable shots, flying close to people or obstacles. They have propeller guards, often mount lightweight cameras (e.g. GoPro Naked).

Freestyle - Acrobatics, smooth transitions, creative flying. Freestyle drones have sturdy frames and great configuration options.

Racing - Speed, maneuverability, low latency. Priority is given to low latency, minimum weight and maximum speed.

Whoop - Small, often 1-2 inch drone with propeller guards (ducts). Designed to fly safely in tight spaces, rooms and even among people. Popular for learning and flying at home.

Image and transmission

Choosing the right transmission and goggles for us is a very important sub-point when creating an FPV kit. We need to answer the question of whether we care about sport flying, or whether, however, we want to focus on recording and quality? Analog transmission is much faster and cheaper than digital, but you don't get very good transmission quality here.

Types of signal sent to the goggles:

• Analog (e.g., 5.8 GHz VTX) - Low latency, affordable, but inferior image quality and susceptibility to interference.
• Digital (e.g. DJI FPV, Walksnail, HDZero) - High HD quality, better readability, but usually higher latency, higher price, more advanced hardware.

FPV Camera - Small camera (analog or digital) mounted on the front of the drone. It transmits real-time images to a video transmitter, enabling "first-person perspective" flight. Features: FOV (viewing angle), latency (delay), resolution. Popular Brands: Caddx, Runcam, DJI. It connects to a video transmitter, which changes the signals from the camera and sends them to the goggles. It is usually available in a kit with a transmission module.

Latency - The delay between the actual event and its appearance in the goggles. Crucial for fast and precise flight. Lower latency = better control. Analog systems have a delay of 10-15 ms, digital (e.g. DJI) from approx. 20 to 50 ms depending on settings and video transmitter.

Components and subassemblies

Each part has a specific function and affects the operation of the entire system. To build, repair or consciously modify a drone, it is useful to know the basic components of its electronics and how they work together.

Below we describe the most important components used in FPV drones - from the flight controller, to the power and motor speed control systems, to the modules responsible for video and radio signal transmission. Knowledge of these components allows not only to better understand the operation of the drone, but also to adjust its performance to meet specific needs.

AIO - All-In-One - A board that combines several devices-usually a Flight Controller (FC) and an ESC (Electronic Speed Controller)-in a single unit. Used mainly in microdrones and small quads (e.g. 1-3 inches), where space and weight savings are paramount. Makes it easier to install, reduces weight, but if one system (e.g. ESC) fails, the entire AIO needs to be replaced.

FC - Flight Controller - Central drone control unit - processes data from inertial sensors (IMU, gyroscopes, accelerometers), commands from instruments and algorithms (e.g. PID). Based on them, it regulates the operation of engines through ESC, stabilizing the flight. Popular software options include Betaflight, iNav, ArduPilot - the choice depends on the application: freestyle, racing, cine, or autonomous missions.

ESC - Electronic Speed Controller - Regulates the voltage passed to the motors and controls their rotation in real time. Receives signals from FC and instantly adjusts the speed of each motor. Can be single (1 pc./motor) or 4in1. Modern ESCs use protocols like DSHOT600/1200 for low latency and greater precision.

VTX - Video Transmitter - Video transmitter that sends video from FPV camera to goggles or pilot monitor. They differ in transmission power (e.g., 25 mW to 1 W), channels and signal quality. The higher the power (mW), the greater the range, but also the greater the power consumption and interference. Often VTXs have the ability to change the power (SmartAudio) through the OSD or the instrument cluster.

VRX (Video Receiver) - Video signal receiver. Can be built into FPV goggles or as an external module. Supports analog or digital transmission standards. In analog systems, diversity receivers are popular - with two antennas to select the best signal. In digital (e.g. DJI, Walksnail) the quality of transmission depends mainly on the transmitter-receiver pairing.

RX (Receiver) - Control signal receiver - receives commands from the apparatus (TX) and transmits them to the FC. Most commonly mounted on a drone. Must be compatible with a transmission protocol, such as ELRS (ExpressLRS), FrSky, Crossfire, FlySky. Modern RX often have telemetry, i.e. a return channel that informs pilots about battery voltage, RSSI, signal quality, etc.

TX (Transmitter) - The control apparatus that the pilot holds. Sends commands via the selected protocol (e.g. ELRS, FrSky, Crossfire) to the receiver in the drone. Modern instruments have programmable buttons, profile configurations, displays, and support OpenTX, EdgeTX or other firmware. External modules (e.g., Crossfire Nano, ELRS JR) are often used to change the protocol.

BEC (Battery Eliminator Circuit) - A module that reduces the voltage from the main power supply (e.g., 4S = 16.8V) to an electronics-safe value (e.g., 5V for RX or camera). It comes as a built-in FC, ESC, or separate module. Protects sensitive components from overvoltage.

Power supply and connectors

Batteries play a very important role in building an FPV drone. Voltage matters, but so does weight and capacity. Often the dimensions alone can also affect the weight distribution and center of gravity of the drone:

LiPo (Lithium Polymer) - Most commonly used battery type in FPV drones. Provides high current capacity, which is crucial for violent maneuvers. It has a low internal resistance and allows very fast current return (the higher the C-rating, the faster the battery returns current).

• Sensitive to overcharging and deep discharge - can swell or catch fire.
  
• Nominal voltage: 3.7 V/cell (full: 4.2 V, discharged: approx. 3.5-3.6 V)

LiHV (Lithium High Voltage) - LiPo variety that allows higher charging voltage - up to 4.35 V per cell (instead of 4.2 V).

• Increases available voltage and thus flight time.
• Popular in microdrones and racing drones, where every hundredth of a second counts.

Li-Ion (Lithium-Ion) - Cells often used in long range FPV and drones for long flights (sometimes as long as >20 minutes)

• Lower discharge current (C), but much higher capacity (Wh) at the same weight.
  
• Not suitable for aggressive maneuvers - engines may not receive enough power.
  
• Nominal voltage: 3.6-3.7 V/cell, full: 4.2 V, minimum: 2.5-3.0 V
  
• Popular cell models: Sony VTC6, Molicel P45B

Power connector types:

• PH2.0 - older, popular in the simplest 1S microdrones
• BT2.0 - PH2.0 improvement: lower voltage drops, better current flow
• BT3.0 - new BetaFPV connector adapted for 2S
• XT30 - used in small 2-4S drones
• XT60 - most commonly used in 5" drones (4S-6S)
• XT90 / AS150 - For large drones and high current applications

Software and regulation

Completing the kit is not enough, it also needs to be programmed properly. We have access to every parameter in the program to make everything work well, it is necessary to go through the calibrations and hardware settings. While most of the ready-made kits are already pre-configured, it is worth knowing about the possibility to set the drone to your preferences.

PID (Proportional, Integral, Derivative) - Flight controller parameters that determine how the drone responds to position/angle errors. Improper settings can lead to instability, excessive vibration or delayed response. Good PID settings are the key to smooth, stable and precise flight.

Rate - Parameters that determine how fast the drone rotates around its axis due to the movement of the rods. High rate = aggressive response (e.g. for freestyle), low rate = smoother and more precise control (e.g. for cinewhoop recordings).

Expo (Exponential) - Reduces sensitivity in the middle range of the stick, but maintains full range of motion at maximum swings. This allows you to fly accurately with small adjustments, while having quick reactions to larger movements.

Blackbox - Flight data logging function (e.g., vibration, yaw, PID, voltages). This data is analyzed in programs such as Betaflight Blackbox Explorer, which helps with PID tuning, vibration detection and improving the drone's behavior.

OSD (On-Screen Display) - Graphical interface superimposed on the FPV camera image, showing information such as battery voltage, flight time, RSSI, flight mode, horizon, GPS, etc. In digital systems, OSD can be integrated with a flight controller or video system.

Summary

The world of FPV drones opens up opportunities to create your own hardware configurations. We are able to properly select parts for the specific task at hand. Unfortunately, many of the terms and parameters can be daunting for novice drone makers. Fortunately, more and more ready-made solutions are appearing on the market, but in order to choose well it is still worthwhile to have a preliminary look, so as not to buy the wrong equipment for us.