Welcome to the Ultimate Guide to FPV Flight Controller! If you’re interested in flying drones or other remote-controlled aircraft, then you know that the flight controller is one of the most important components of your setup. It’s the brain of your aircraft, controlling everything from its movement to its stability and performance. But with so many options and features to choose from, finding the right flight controller can be a daunting task. That’s where this guide comes in.
In this guide, we’ll give you a comprehensive overview of FPV flight controllers, including their components, types, and features. We’ll also give you tips on how to choose the right controller for your specific needs and budget, and walk you through the setup and configuration process. In addition, we’ll cover advanced tips for optimizing your controller’s performance.
Whether you’re a beginner or an experienced drone pilot, this guide will give you the knowledge and insight you need to make informed decisions about your FPV controller. So let’s dive in and explore the exciting world of FPV flight controllers!
What is a flight controller?
An FPV flight controller is the device that manages the flight of a drone. It serves as the brain of the aircraft, receiving input from various sensors and controlling its movement and stability. Essentially, it’s the heart of your drone, making sure it flies smoothly and safely.
The Flight Controller is responsible for processing data from the FPV drone’s sensors, including accelerometers, gyroscopes, barometers, and compasses. It uses this data to make real-time adjustments to the FPV’s speed, altitude, and orientation. It also regulates the power output to the motors, which in turn controls the drone’s movement.
How the flight controller works
A flight controller for drones is the central processing unit that controls the flight of a drone. It is a small electronic device that receives input from various sensors, including accelerometers, gyroscopes, and barometers, and uses this data to calculate and adjust the drone’s movement and orientation in real-time.
The flight controller is responsible for controlling the power output to the drone’s motors, which in turn controls its speed and direction. It also regulates the drone’s altitude and stability, making adjustments to keep it level and prevent it from drifting or crashing.
A high-quality flight controller is crucial for the safe and efficient operation of a drone. It can help to prevent crashes, improve flight stability, and allow for more precise control of the drone’s movement.
Different types of flight controllers are designed for different types of drones, such as racing drones, aerial photography drones, or industrial drones, and have specific features and capabilities to suit their intended use.
The history of FPV flight controller
The history of FPV flight controllers dates back to the early days of remote-controlled aircraft. Back then, flight controllers were simple devices that could only perform basic functions such as controlling the drone’s speed and direction. However, with the rise of FPV drone racing and the increasing demand for more advanced flight capabilities, flight controllers have evolved significantly over the years.
One of the key milestones in the evolution of FPV flight controllers was the development of the first multi-axis flight controller. This allowed for more precise control of the drone’s movement and paved the way for more advanced flight features such as acrobatic maneuvers and automated flight modes.
Another important development was the integration of GPS technology into flight controllers. This allowed drones to navigate autonomously and enabled features such as waypoint navigation and automatic return-to-home functions.
Today’s FPV flight controllers are incredibly advanced and feature-rich, with support for multiple flight modes, advanced stabilization algorithms, and customizable settings. Many also include built-in on-screen display (OSD) systems that provide pilots with real-time flight information and telemetry data.
As the drone industry continues to grow and evolve, it’s likely that we’ll see even more advanced flight controllers with new and innovative features. The future of FPV flight controllers is certainly exciting.
Why it's important to choose the right flight controller
Choosing the right flight controller is essential for the safe and efficient operation of your drone. A high-quality flight controller can help prevent crashes, improve flight stability, and allow for more precise control of your drone’s movement.
On the other hand, a poorly designed or inadequate flight controller can lead to instability, crashes, and other problems. It’s important to select a flight controller that is appropriate for your specific drone and intended use, and that has the necessary features and capabilities to meet your needs.
Overall, investing in a quality flight controller is key to achieving optimal performance and safety in your drone flying.
Components of the Flight Controller
Processor Unit (MCU)
The processor of an FPV flight controller is a microcontroller unit (MCU), which is the central processing unit that controls the drone’s flight. The MCU is responsible for running the drone’s flight control algorithms, taking in data from sensors, and making real-time adjustments to the drone’s speed, direction, and altitude.
There are several different types of MCU processors used in FPV flight controllers, including F1, F3, F4, G4, and F7 processors, H7 processors. The main difference between these processors is their processing power and capabilities. F1 processors are the oldest and have the least processing power, while F7 processors are the most powerful and capable.
F1 processors are typically used in entry-level flight controllers and can handle basic flight functions. In 2017, Betaflight will stop supporting F1 FCs.
F3 processors are more powerful than F1 processors and can handle more complex flight control functions. As Betaflight optimizations continue to develop, F3 processors have a hard time keeping up.
F4 processors are even more powerful than F3 processors and are commonly used in mid-range and high-end flight controllers.
G4 processors is an MCU family between F3 and F4.
F7 FC’s became available in mid-2018. F7 processors are the most powerful and capable processors, and are commonly used in high-end flight controllers that require the highest level of processing power and functionality.
The H7 is designed as a faster and more economical alternative to the F7 series.
The clock frequency has been nearly doubled to 400 MHz by improving the semiconductor manufacturing process from 90 nm to 40 nm. This also reduces power consumption.
| Processor | Max Frequency [MHZ] | MAX FLASH [KB] | MAX. SRAM [KB] |
|---|---|---|---|
| F1 | 72 | 1024 | 96 |
| F3 | 72 | 512 | 80 |
| F4 | 180 | 2048 | 384 |
| G4 | 170 | 512 | 128 |
| F7 | 216 | 2048 | 512 |
| H7 | 400 | 2048 | 1024 |
Gyroscopes
The gyroscope, located on the quadcopter, is responsible for detecting its movement and relaying that information to the flight controller. It plays a critical role in the operation of the quadcopter.
When examining gyro parameters on a flight controller, you may notice that some models use the MPU6000 or ICM20608, while others use the BMI270. The MPU is considered the reliable but outdated option, with an 8k update rate limitation. In contrast, ICM gyros can achieve up to 32KHz, but are more susceptible to motor or propeller-generated vibrations. As a result, the MPU6000 is still the preferred choice for most quadcopter pilots.
Firmware
FPV flight controller firmware is the software installed on the flight controller to debug the various parameters of the drone. There are several different firmware options available, each with its own features and functions.
Below are some of the most popular FPV flight controller firmware:
Betaflight: Betaflight is a widely-used open-source firmware that is popular among FPV drone pilots due to its robust features and customizable options. It offers advanced features such as PID tuning, OSD, and blackbox logging, and is continuously updated with new features and bug fixes.
KISS is a proprietary firmware with limited availability, which implies that you have to buy the Kiss flight controller before using it. Compared to Betaflight, KISS has fewer configuration settings, which makes it easy to set up quickly. Many experienced pilots highly recommend the KISS build due to its excellent performance.
FalcoX, also known as FlightOne, is a proprietary firmware that requires you to purchase a FlightOne flight controller before you can use it. One of its standout features is its ease of use, as you can set it up entirely from the on-screen display menu without the need for a computer.
Designed primarily for racing and acrobatic flying, FalcoX is optimized for use with F4 flight controllers. It’s known for its precise and smooth stick feel, which can help pilots perform complex maneuvers with ease. As a closed-source firmware, FalcoX has a limited number of customization options, but it offers a streamlined flying experience that can be ideal for those who prioritize simplicity and performance.
Speedybee offers a convenient way to set up your flight controller using just your smartphone. You can even flash Betaflight/INVA/Emuflight firmware and use the BLHeli configurator via the Speedybee mobile app.
However, being a third-party app, there may be times when pilots experience certain problems with the app. Ultimately, it is up to you to decide if Speedybee is the right choice for your needs.
INAV operates as a Google Chrome app and enables you to set up the INAV software to function on any compatible INAV target. It has the ability to support various types of aircraft including quadcopters, hexacopters, octacopters, and fixed-wing aircraft.
UART
UART is a type of hardware serial port that enables the connection of external devices to the flight controller. Devices such as telemetry, VTX control, LED light strips, and serial radio receivers can be connected to the UART.
Each UART has two pins, one for sending data (TX) and the other for receiving data (RX). Remember that the TX of the external device is connected to the RX of the FC, and vice versa. You can assign tasks to the UARTs in the Port tab of the Betaflight Configurator. For user convenience, almost all F4 flight controllers have a dedicated pad for SBUS where you can solder the RX directly. If this pad is not available, you can use Soft Serial for SmartPort or get the same signal from RX.
BEC output
A Battery Eliminator Circuit, or BEC for short, is a voltage regulator that steps down the main battery voltage (e.g. 14.8 volts) to a lower voltage (usually 5 volts) to safely power the receiver and servos. The output voltage of a BEC on most FPV flight controllers typically ranges from 5V@1A to 5V@3A, depending on the model.
OSD Function
The OSD function of an FPV flight controller stands for On-Screen Display. It allows important flight data such as battery voltage, flight time, and GPS coordinates to be superimposed on the video feed sent to the FPV goggles or monitor. 
This data can help pilots monitor their drone and make adjustments during flight. In other words, the OSD function displays useful information about the flight on the screen so the pilot can stay informed and aware of what’s going on.
BlackBox
The blackbox is a device that records flight information such as the drone’s orientation and helps with tuning. You can record data in two ways: to an SD card or to the built-in flash memory.
If your controller doesn’t have an SD card or flash memory, you can get an external SD card reader (Open Logger) and connect it to your controller via the UART. Not all controllers have a built-in blackbox feature, so check before you buy if you want to use the data to adjust filter parameters for stable flight and reduced motor overheating and vibration.
Boot Button
Pressing this button puts the Flight Controller into bootloader mode, which allows you to manually update the firmware if the standard firmware update procedure fails.
USB Ports
Flight controllers typically have either Micro-USB or Type-C connectors, with Type-C offering faster data transfer than Micro-USB. Plus, as more and more electronic devices use Type-C, you’re more likely to have a Type-C charging cable on hand, making it a convenient choice for flight controllers. That’s why I prefer flight controllers with Type-C connectors.
Types of Flight Controller Connections
Flight controllers have three types of connectors:
1.Solder Pads
2.JST Connectors
3.Solder Holes
JST connectors are especially convenient for beginners to connect FPV accessories, as they are plug and play. Solder pads and solder holes require you to solder one end of the wire to the controller and the other end to the accessories.
Mounting Size
The most commonly used mounting patterns in quadcopters are 16×16 (for quads under 2″), 20×20 (for quads between 2″ and 4″), and 30.5×30.5 (for quads 4″ and larger). This measurement refers to the distance between each hole in the FC. 
When purchasing a Flight controller, make sure it matches the mounting pattern specified for your frame. Some frames support both 20×20mm and 30.5×30.5mm hole patterns, so be sure to select an appropriately sized Flight controller that matches your frame.
Additional Sensors
Barometer
The barometer is a sensor that measures air pressure, which is used by the flight controller to estimate the altitude of the drone. By comparing the barometric pressure at the drone’s current location to a reference pressure, typically sea level pressure, the flight controller can calculate the drone’s altitude. This is important for maintaining stable flight, especially when flying in autonomous modes such as altitude hold or return-to-home.
Magnetometer
The magnetometer is a sensor that measures the strength and direction of the magnetic field around the drone. This is used by the flight controller to determine the drone’s orientation, or heading, with respect to magnetic north.
By combining data from the magnetometer with data from other sensors, such as the gyroscope and accelerometer, the flight controller can accurately track the drone’s position and movement in three-dimensional space. The magnetometer is particularly important for drone navigation and control in GPS-denied environments, such as indoor flying or areas with heavy magnetic interference.
Types of The Flight Controllers
FC single | AIO FC
AIO FC refers to the integration of the flight controller and electronic speed controller (ESC) on a single board, which includes components such as the processor, gyroscope, OSD chip, and BEC.
For drones that are 2 inches or smaller, it is recommended to use an AIO FC with a 25A ESC. For drones that are 2 inches or larger, an AIO FC with a 45A ESC is recommended to reduce the risk of ESC burn out due to high peak current during flight.
How To Buy The Right Flight Controller For You?
Whether you’re a beginner or an experienced pilot, there are a few things to consider when buying a controller to make sure you get the right one for your needs.
First, consider the size of your drone and the mounting pattern on the frame. You want to make sure the controller you choose is the right size and has the right mounting pattern to fit your drone.
Next, think about the features you need. Do you want a controller with a built-in OSD, a black box, or something else? There are some flight controllers that have a SpeedyBee Bluetooth/WIFI tuning module built right in, which allows you to tune directly with your phone, making tuning even more portable. These additional features also need to be considered for your budget, as they can add to the cost.
It’s also important to consider the performance of the F4 or F7 processor and sensor you purchase. Choose a flight controller with a fast processor and reliable sensors such as gyroscopes, accelerometers, barometers, and magnetometers for better flight performance.
The ability to access more peripherals plugs on the flight controller is another factor to consider. You need one for the video transmitter, one for your receiver, one for the buzzer, one for the LED, etc.
A proper flight controller pad layout may also be one of the factors you consider when purchasing a flight controller. A properly laid out pad design determines whether the cable layout is convenient and can lead to a better experience when building a drone. Some flight controls have plug-and-play ports so you don’t need to solder cables.
And finally, whether the customer support for the brand of flight controller you are considering will be patient enough to help you with any problems you may encounter. This is particularly important for beginners!
Keeping these factors in mind will help you make an informed decision when choosing the right flight controller for your drone.
How to setting up and configuring the FPV flight controller？
Setting up and configuring an FPV flight controller involves several steps. Here are the general steps you can follow:
- Connect the flight controller to your computer using a USB cable and open the Betaflight Configurator software.
- In the Betaflight Configurator, select the correct port and baud rate for your flight controller, then click “Connect”.
- On the “Setup” tab, configure your flight controller’s basic settings such as receiver type, motor direction, and min/max throttle values.
- On the “Ports” tab, select which ports you want to use for your peripherals such as receiver, GPS, OSD, etc.
- On the “Configuration” tab, set up your flight modes, arming and disarming procedures, and other advanced settings.
- On the “PID Tuning” tab, fine-tune your flight controller’s PID settings to optimize its flight performance.
- Once you’ve finished configuring your flight controller, save your settings and disconnect it from your computer.
You may need to refer to the user manual for your specific flight controller to find the exact steps and settings you need to configure.
Tips for FPV Flight Controllers
PID Tuning and Optimization
PID tuning and optimization is an advanced technique that can greatly improve the performance of your FPV drone. PID stands for Proportional, Integral, and Derivative, which are the three control terms that work together to help stabilize your drone in the air.
Here are some tips for PID tuning and optimization:
Start with the default settings: Before you start tuning your PIDs, make sure you are using the default settings in your flight controller. This will give you a baseline to work from.
Test in a controlled environment: When tuning your PIDs, it’s important to test in a controlled environment, such as a large open field with no obstructions. This will help you focus on your drone’s performance without worrying about crashing into something.
Make small adjustments: When making adjustments to your PIDs, it’s important to make small changes at a time. This will help you avoid making big changes that can cause your drone to become unstable.
Test one axis at a time: It’s best to test one axis at a time, starting with the pitch axis, then the roll axis, and finally the yaw axis. This will help you focus on each axis separately and fine-tune each one.
Record your changes: As you make changes to your PIDs, be sure to record them so you can go back and compare your results. This will help you see the effects of each change you make and help you fine-tune your settings.
Use a simulator: Using a simulator can be a great way to test your PIDs without risking damage to your drone. This allows you to fine-tune your settings in a safe environment before taking your drone out for a real flight.
Be patient: Tuning your PIDs can take time and patience, so don’t rush the process. Take your time and make small adjustments until you find the perfect settings for your drone.
Recommended stacks for beginners
SpeedyBee F405 Stack – F405 V3 FC + 50A 3-6s BLHeli_S ESC
XRotor Stack – F7 FC + 40A 4-in-1 BLHeli_32 esc
Diatone Stack – MK4 F722 APP FC + 45A 3-6S BHeli_32 128K ESC
You can check this post for more information about them.
Conclusion
There are many factors to consider when choosing a suitable FC, and as a beginner you may feel overwhelmed at first. I was once a beginner and spent several weekends learning the basics of quadcopters, but now I have a good grasp of the subject.
I recommend that you read this article thoroughly to avoid missing any important information. Once you have a good understanding of the subject, you will no longer need to search the web for articles to fill in any gaps in your knowledge.
