Flying RC planes and multi-rotors is fun, but strapping a camera on your plane, some video goggles on your head, and flying as if you’re on the plane fucking amazing. That’s first person view or FPV, and the best part is that if you’ve already got a plane or multi-rotor, you get everything you need for around $80 USD.
Things you need to know
Like when you first get into RC flying, there’s a lot of stuff you need to know in order to make informed decisions when buying FPV gear. Some of the terminology can be pretty indecipherable too. I’ll try to explain as much as I can, or link to others who do.
- Some planes are better than others for FPV. Slow “pusher” (prop on the back) designs are better for beginners.
- Video and RC frequencies (if not sure, just use 2.4GHz for RC, and 5.8GHz for video).
- Antenna choices – RHCP vs LHCP, SMA vs RP-SMA.
- More transmitter power does not necessarily mean more range.
- Expensive goggles are a trap if you are interested in VR – once the Oculus ships, it will make a great headset!
- Voltage matching camera/transmitter and power supply.
Components of an FPV system
An FPV system has two main components: the transmitter, which captures and transmits video, and is attached to your plane; and the ground station, which receives the video signal and displays it on a screen or set of goggles.
The transmitter consists of:
- A camera, usually a 1/3″ or 1/4″ CMOS re-purposed security camera.
- A wide-angle lens, anywhere between 110 and 150 degree field of view is good. Too small (the standard lenses are 90 degrees) and it’s like driving while looking through a pair of binoculars.
- A transmitter module, which typically has a band/channel selector so you can choose the frequency it transmits at – this is useful if you’re flying with friends and don’t want to interfere with their signal.
- An antenna, ideally an omni-directional circularly polarised clover-leaf antenna (three lobes).
- Power supply, which can either be stand-alone, or draw from the plane’s main power in which case some filtering and/or voltage regulation is needed.
The ground station consists of:
- A receiver, that’s compatible with the transmitter module (usually this comes down to transmission frequencies).
- An antenna, ideally an omni-directional circularly polarised skew planar wheel antenna (four lobes).
- A monitor or set of goggles, which must not show a “blue screen” when the signal gets too low like modern TVs. Usually this means you have to buy purpose-built FPV screens.
- Power supply, usually somewhere in the vicinity of 12 volts, so a 3S lipo battery works well.
The baseline price
The only cons to this system are that the transmitter portion is comparatively heavy, which is fine if you have a big plane or a powerful multi-rotor. But if you want something lightweight you can strap on a small plane, you have to DIY.
To power the transmitter portion of the kit, you can either use a separate 2S lipo battery, or wire into your plane’s main power. If you do this, I recommend using a lightweight DC step-down voltage regulator to set the voltage to 9v. This has two advantages – the transmitter and camera run cooler the lower the voltage you feed them, and “noise” created by the ESC and motor get filtered out. Plus, they’re only $0.66 USD.
A DIY lightweight FPV transmitter
If you want to go lightweight, you have to assemble the transmitter portion yourself. You could still buy the kit above to use the ground-station parts of it, and save the transmitter bits until you get a larger plane – this is what I did.
There’s lots of instructional videos on assembling the components of the transmitter, or “FPV backpack”. I started with the Kiwi guy who runs RC Model Reviews, which are a bit dated, but explain all the concepts really well. Much better is Flite Tests’ article and video, which are spot on.
There’s also this dude Arxangel who coincidentally bought the same small plane as me (the Firstar 200) and built a little FPV setup into it. His post is worth a look.
Bill of materials
- Camera: Tiny 1/4″ CMOS 3-5v wide-angle $14.70 from Aliexpress
- Transmitter module: Boscam TX5823 200mA 5.8GHz 8 channel $9.25 from Aliexpress
- Antenna: 5.8GHz LHCP RP-SMA $5.95 for a Tx/Rx pair from Aliexpress – if you only need the Tx, you might be able to find cheaper
- Power supply: Mini LM2596 voltage regulator module $0.66 from Aliexpress
- DIP switch: 10 pcs three pole $1.95 from Aliexpress
- Fine gauge wire – just strip the cable that comes with the camera.
Total cost: $32.50 USD which includes global delivery.
- Fine tip soldering iron
- Glue – I recommend apoxy, though gel super-glue is ok. Hot melt glue can work, but the transmitter modules can get hot enough to re-melt the glue…
- Multimeter (to set the voltage output on the regulator to 3.3v)
- Third hand desktop soldering vice. If you don’t own one of these, go and buy one NOW. I didn’t for years and have regretted it ever since I got my hands on one.
Other things you might want
- Velcro – to attach the module to your plane, helps with vibration and makes taking it off easier if you break it.
The build is basically identical to what’s shown in the Flite Test and Arxangle articles above, with a couple of differences.
- Make sure you get a transmitter module and camera that operate at 3.3v. This avoids the need for extra capacitors and voltage regulators which are a pain to solder and just add weight. They’re also less efficient too. The camera and tx module listed above are both 3.3v.
- Chop the silly RP-SMA connector off the tx antenna and solder it directly onto the tx module. Don’t ever power on the tx without an antenna attached – this kills the module.
Ground station, if you don’t buy the kit
If you don’t buy the HobbyKing kit, you’ll still need a receiver module and a monitor.
- HobbyKing sell the Quanum goggles seperately for $30 (not including delivery).
- You can find the Boscam RC832 receiver for $21 on Aliexpress.
- You’ll still need the 4-pole 2.5mm to RCA cable, and a power connectors for the goggles (the RC832 comes with one, but even then you’ll probably want to modify it).
Seriously, just buy the kit.
Bonus ground station things
This also gets the weight of the receiver off your head, and means you can use an extension lead to give you a bit more freedom with the goggles.