If you’re a reader who has experience flying RC airplanes, or who has read about the basics of RC flying, this article will help you get started in setting up your first FPV system.
Sourcing Your Equipment
In the last couple of years, various vendors have started to sell kits that contain the minimum FPV system components needed to outfit an RC aircraft for FPV flight. ReadyMadeRC sells such kits. In some cases, such as at ReadyMadeRC, these kits are comprised of good quality parts. In many cases, however, you could do better by selecting the components individually.
Which company you use to source your FPV system equipment depends in large part on where you’re located. In the past, those of us in the US had to pay hefty shipping fees for batteries and parts from overseas. But now, there’s many more options for domestic shipping. If you’re overseas, you’ll have to find a vendor with a large stock of items and reasonable shipping rates. HobbyKing has an international warehouse and may be a good option. Take a look at some of the other companies on the FPV Links Page to see if they’ll suit your needs.
FPV System Minimum Requirements
Let’s go through the various items you’ll need to upgrade your RC aircraft for FPV use. Refer to the picture below for a graphical representation of how these items work together.
For a complete discussion of FPV camera types, read the post about FPV cameras. The cameras used in FPV are the same as those used in many security cameras around the world. You can get an inexpensive CMOS camera for around $40 – $50. The camera section at ReadyMadeRC has some nice options. One thing you do need to be aware of is the power requirement for your particular camera. It’s a good idea to select a camera with a wide input voltage range, so that you will have some flexibility when wiring your system. I like to use cameras with a 5-15 V input, so that I can use the main flight battery (3S 12.6 V max) for power.
A basic foam trainer is all you need to start flying FPV. You might want to read the last few paragraphs of this article for some ideas on good starter planes. Even experienced RC pilots who are used to line-of-sight (LOS) flying may want to stick to something more basic for the first few FPV flights. If you’re most comfortable flying a quadcopter or another type of aircraft, you could also use that as your FPV platform. The best starter aircraft for FPV is whatever you’re most comfortable flying LOS.
3. RC Transmitter and Receiver
If you’ve just got a simple RTF trainer kit that came with an RC transmitter, chances are the control frequency is 2.4 GHz. Which video feed frequency you should use will depend on the frequency chosen for your video feed, the environment in which you fly, and personal preference. Read the page on selecting control and video frequencies to learn more about choosing the best frequencies for your FPV system.
4. and 5. Video Transmitter and Antenna
The video transmitter takes the signal from the camera and sends it out an antenna. The transmit antenna is an omnidirectional antenna. An omnidirectional antenna sends the signal out in all directions, like an ever-expanding beach ball. In reality, the signal doesn’t propagate in a perfectly omnidirectional way, but that analogy describes the general idea. Video transmitters are typically designed for use in one of several frequency bands. A selector switch on the transmitter will set the exact frequency for the video signal transmission. Your choice of frequency will depend on several factors. You can find more information on selecting video frequencies in the same article linked above, and again here.
6. and 7. Ground Station with Video Receiver and Antenna
A ground station just refers to the several components that receive and display the video feed. Ground stations can be simple or complex.
In the diagram above I show a larger tripod setup with two antennas. For simplicity, I would start with an omnidirectional, circularly polarized receive antenna connected to a video receiver. You can just Velcro the video receiver to the side of the monitor. The picture to the right shows two omnidirectional antennas, each connected to a video receiver. Only one receiver should be used at a time. I was testing the two antenna / receiver combinations when this picture was taken, and that’s why you see two antennas and two video receivers. The output of the video receiver is connected to the video display. A 4000 mAh 3S battery (off screen) powers the video monitor and video receivers.
Antenna selection is an important topic in RC FPV. The type of antennas used can make or break an FPV system. For more information, watch Alex Greve’s antenna selection tutorial video.
8. Video Display: Monitor or Goggles?
Video goggles have two small displays inserted into a small headset. You’ll get an immersive experience that’s a lot like sitting in the front row of a movie theater.
Although the video looks great, they can be cumbersome to use – especially when flying alone. If you need to take a look at your transmitter or adjust something on your ground station (like when the wind knocks it over) you’ll have to reorient yourself while maintaining control of the aircraft via LOS. For a beginner FPV pilot, I would recommend going with a simple 7″ video display monitor like the one shown below:
7 Inch FPV Monitor For RC Models ‘Aero’ – Sun Shield, Adjustable Video System, Anti Video Black Out Technolgy
Although any display monitor can be used, those designed specifically for FPV are best. Many general use monitors and flat screen displays will switch to a ‘blue screen’ if a video input signal is not of high enough quality. Unfortunately, few monitors have an option to turn off this function. Watch this video on the difference between the blue screen and a continuous video display.
Wiring Your Basic FPV System
You’ve determined which frequencies you want to use for RC and video, and purchased the necessary components to make your FPV goal reality. Now it’s time to wire all these items together into a wireless video system.
One tip to help make this process go more smoothly is to recall the operating voltage of each component. Video transmitters and receivers typically operate at 12 V. Many cameras also have an operating voltage range that includes 11-12 V. By using components that operate at 12 V, it will be easier to wire straight off of a 3S (12.6 V max) main battery supply. You’ll have to use additional voltage transformers to step down the voltage if you plan to use 4S batteries (16.8 V max).
One thing to be aware of when using the power straight off a battery is the minimum operating voltage for the video transmitter and camera. Although a 3S battery may start out at 12.6 V at full charge, during use the voltage of the cells will drop down to as low as 3.2 V*. You’ll want to make sure that the operating voltage of your FPV system components encompasses at least this 9 V threshold.
* Note: You could discharge the batteries to a lower voltage, but then they won’t take a charge. Read this article for more information on LiPo batteries.
Here’s a wiring diagram for a simple FPV system:
You can use standard servo wire for all connections, except from the battery to the speed controller, and from the speed controller to the motor. Servo wire is typically 22-26 AWG, and can tolerate at least several amps of current. Speed controller UBECs are typically rated for 3 to 4 amps output. Servo wires will carry this current with no problem. The UBEC output powers the servos and RC receiver.
The yellow wire on the right of the diagram carries the video signal from the camera to the video transmitter, shown in the upper right. The wire doesn’t have to be yellow in color, it’s just convention. This diagram represents a single battery powering both the video link system and the control / power system.
If you use a single battery to power both, a power filter is highly recommended. Note the prominent position of the power filter in this diagram between the split to the motor controller and the split to the camera / video transmitter. While the power filter is optional for functionality, your video feed will be much clearer if you use it.
The white wire you may notice in the picture of the video transmitter is reserved for audio or telemetry information. For now, you can ignore it. You might want to leave it attached, but out of the way, in case you want to add additional functionality to your FPV system.
The ground station is wired in much the same way, except you have a video receiver and a monitor instead of a video transmitter and a camera.
Once you understand the various components that make up a basic FPV system and how to wire those components into a functioning circuit, you should be ready for your first ground test and maiden flight.
Here are some useful articles to review: