Grant NovotaFPV Drones
Introduction
Drone use in general has increased greatly in recent years, with many different types of drone technologies becoming available. FPV drones have increased in popularity in both the commercial and recreational sectors, as more and more people are starting to discover the many unique advantages that they provide over traditional commercial drones, such as the popular DJI Mavic product line. The most popular commercial use for FPV drones is for filming. FPV drones are capable of filming unique perspectives due to their ability to fly fast, handle complicated maneuvers, and be flown very precisely around the environment that they are in. The next most popular use by professionals is drone racing. The same advantages that these drones have for filming makes them capable of being used for competition, where pilots race their drones through complex race tracks that contain many obstacles. Many people also enjoy using these drones recreationally, to film, race, and just have fun with the unique experience of piloting these devices.
Videos
My FPV drone videos can be found on my youtube channel: Grant Novota
My FPV Racing Drone
A List of Main Components:
- Carbon fiber frame
- Caddx Vista Digital HD FPV Air Unit
- Albatross LHCP RP-SMA 5.8g antenna
- 5 inch 3-blade propellers x4
- SucceX-E F4 Flight Controller
- SucceX-E 45A 2-6S 4-in-1 ESC
- XING-E brushless motors x4
- 6S batteries
Architecture:
There are 3 main components within the center of the drone frame that work together to control the aircraft. The drone is controlled by a flight controller board, which is powered by a microcontroller with a 32-bit ARM Cortex architecture that is running an opensource flight software build called Betaflight. This microcontroller is the brain of the operation and contains 512 kb of flash, 128 kb of SRAM, and may communication interfaces such as USB, SPI, I2C, and UART. The controller board features some open solder pads to these communication interfaces, so that the drone owner can connect more devices to the drone if desired (GPS, LEDs, speakers, etc.) and the Betaflight GUI easily allows the integration of new devices into the embedded flight software. The microcontroller chip is complimented by many other onboard components that work together to create the flight controller. The on-screen display (OSD) generator chip adds telemetry to the video signal that is sent to the goggles, which is customizable within the Betaflight GUI and may contain data points such as battery voltage, current draw, and flight time. Another important component on the flight controller board is the inertial measurement unit IMU chip, which is used to communicate movement data so that the drone is aware of its position in 3D space. The drone is capable of operating in a “stability” mode for easy piloting, which relies heavily on data from this sensor to keep the drone level with the horizon. The flight controller also contains the power electronics circuitry. It contains buck converters, which are used to convert the high voltage of the battery into the lower voltages needed for the microcontroller and other chips contained on the board. More details on powering the drone will be covered in the power requirements section of this product breakdown. Finally, the drone’s flight controller board contains many smaller components, such as resistors, capacitors, inductors, LEDs, a USB port, and buttons.
The flight controller board is stacked on top of the electronic speed controller (ESC) board. This is what drives the four motors of the drone that spin the propellers and allow it to fly. The ESC board contains four microcontrollers, one for each motor, and they are running firmware called BLheli, which is not open-source like Betaflight. The board also contains six mosfets per motor and each motor is connected by three wires. These convert the DC voltage from the battery into AC voltage (3 phases), which is what drives the brushless motors. A connector between the flight controller board and ESC board allows communication between the two.
The third main component on this drone is called the Caddx Vista Air Unit. This is what contains the FPV camera, which is extended to fit into the front of the drone frame and provide the pilot with the first-person video feed while operating the aircraft. It is also what handles communication with the FPV goggles and remote controller, and it passes commands from the remote controller to the flight controller board through a wired connection. It contains a single antenna, which extends out of the back of the drone frame. The Caddx Vista component is more closed off than the other two main components in the drone and its hardware and software design details are not available to the public.
Power Requirements:
The drone is powered by a 6S battery, which is typically plugged into the drone starting at its full charge at 25.2V (4.2V per cell x 6 cells) and is removed from the drone before the voltage drops to 19.2V (3.2V per cell x 6 cells) to avoid damaging the battery. FPV drone power requirements can very a lot depending on the size/type of drone and 1S6S is the battery range that they most commonly use. My racing drone is capable of operation using 4S, 5S, and 6S batteries, but flies best with 6S batteries because more power is available to the motors. The battery is only plugged into the drone when the pilot intends to fly and remains disconnected otherwise because there isn’t any kind of battery separation switch in the drone design, so if the battery were to be left plugged in, the drone would quickly overheat and discharge the battery to the point of damaging it. Flight time is extremely variable depending on how the pilot chooses to fly the drone. Flying more aggressively or in windy weather results in more power draw and shorter flight times, while cruising in mild weather conditions induces less stress on the battery and allows for longer flight times. Through personal experience, I’ve found that a 6S battery that has 1400-1500mAh capacity (typical for 6S FPV drones due to weight concerns) will allow flight times between 3 and 5 minutes. Many of the modern-day commercial drones (non-FPV) such as the DJI Mavic product line are capable of extending flight times to 20-30min using similar battery capacities. This is because they are essentially piloting themselves with the goal of maximizing efficiency. FPV drones are typically flown much more aggressively to race or perform tricks.