One of my original goals for drone research was to build a machine capable of taking excellent aerial videos of Alaska. Here are some of my first attempts:
This year my roommate Calvin and I bought full mascot-sized Cookie Monster and Elmo costumes for Halloween. I was Elmo. It was awesome.
The morning after Halloween, our drone enthusiasts group met up for a fly session. I decided to fly FPV in the Elmo head.
I’ve been experimenting with recreational drones for 18 months now. After a lot of late nights and iterations, I have a quadcopter that I’m very happy with. It’s going to get amazing backcountry skiing video this season.
- 50-60mph forward flight
- 5-6 mile control range
- 1-2 mile line-of-sight video range
- ~15 minute battery flight time
I’m using a QAV400 frame from GetFPV, but with a special twist. I installed longer motor arms from the QAV500 so I can use 10″ propellers (instead of the 8″ props that QAV400 arms are limited to). Longer props give more power, efficiency, and stability.
Flight Controller - My copter is driven by the fantastic 3DRobotics Pixhawk.
Motors - I’m using T-Motor’s 1100kv. These have been crazy powerful, and after months of hard flying they’re still running great. I bought a set of SunnySky 1100kv motors to try when my T-Motors are toast.
ESCs - The Lumenier 30A ESCs from GetFPV have provided plenty of power and I’ve had no issues so far.
Camera Gimbal - GetFPV’s Plug-and-Play Gimbal was expensive, but it’s been completely worth it. My videos went from very bumpy to very smooth in about 30 seconds of frame adjustment.
Camera - GoPro Hero 3 – I use the GoPro for both FPV (live video output) and for recording. People used to warn against this, but after months of flying I’ve had no issues.
Live Video Transmitter - ImmersionRC’s 600mW 5.8GHz transmitter, with a 3D printed enclosure from the RCGroups FPV forum. This gets me about 1km of range with SpiroNet Omni antennas on both receiver and transmitter. Using a helical antenna on my goggles, I can get 3-4km.
Video Antennas - SpiroNet RHCP (right hand circular polarized) omni antennas
RC receiver - EZUHF’s 8-channel Lite receiver. Though in the future I’ll use a 4 channel because you can squeeze 8 channels into one with PPM!
I’ve been flying ‘First Person View’ (FPV) for about 1 year now. FPV takes place when you control a vehicle remotely by watching a live video feed from a camera on the vehicle. It’s a fucking blast.
My ‘for science’ (for-fun) goal with FPV is to experiment with long range, but generally I want to fly reliable distances with very compact gear. I don’t want a huge ground station. I want to backpack/ski into the backcountry with a flying robot and some video goggles — the lighter the gear the better. For geeks looking to get into FPV, these are my key takeaways after using 5.8GHz for FPV over the past year.
1. 5.8GHz VS other frequencies?
There are three popular frequencies for transmitting analog FPV video: 5.8GHz, 2.4GHz, and 1.3GHz (I left out 900MHz because I haven’t seen many people using that today, though it is used). I’ve only been able to test 5.8GHz, so keep that bias in mind.
I’ve had GREAT and HORRIBLE results with 5.8GHz based on the gear used, but by now I’ve concluded that it IS POSSIBLE to get amazing FPV results with 5.8 — you just need to do it right.
Advantages of 5.8GHz:
- Very small antenna size — compact and easy to travel with
- No interference issues with any radio control system (2.4GHz and 433MHz are the popular control frequencies)
- Great video quality
Disadvantages of 5.8GHz:
- Poor obstacle penetration — hard to go around trees and buildings
- Shorter range compared to other frequencies without time invested tweaking (testing channels and antennas)
1.3GHz is a great frequency for video because of its robustness. I have friends that have reported 3+ miles of clear video range using 1.3GHz in crowded areas with lots of radio frequency noise. I’ve read posts and seen videos of people getting 10-20 mile range in open sky. Wow!
I tried using 1.3GHz a few months ago and ended up going back to 5.8GHz. The 1.3GHz video transmitter I tested drowned out my 2.4GHz RC control, and my control range dropped significantly. I didn’t want to worry about losing control of my copter in the air, so I decided to keep tweaking my 5.8GHz system and then upgrade to 1.3GHz or 2.4GHz after changing my control frequency. The big downside to 1.3GHz is the size of the antennas. They’re HUGE!
2.4GHz summary/comparison (what I’ve read):
The infamous Team Black Sheep seems to swear by 2.4GHz for FPV, which is a huge endorsement. TBS videos are what got me into FPV, so I am always considering switching to 2.4GHz. 2.4GHz has much better object penetration than 5.8, so it’s easier to fly behind trees, buildings, mountains, etc.
The problem with 2.4GHz for video is that most RC Transmitters use 2.4GHz for control. This means you have to use a different frequency for control if you want to use 2.4GHz for video. UHF (433MHz) is the most popular long-range control frequency. It just costs time and money to switch. 2.4GHz antennas are slightly bigger than 5.8GHz, but it’s probably worth that for the instant range gain and obstacle penetration. However, 2.4GHz is used for a lot of different things in the industrial world (Wifi and wireless home telephones are some examples) so be careful using 2.4GHz for video in populated areas.
I love 5.8GHz purely for its convenience and quality. I really like maximizing efficiency. I just bought an antenna that should get me 4-5km of video range with 5.8GHz in open skies. However, I’ll probably bite the bullet and upgrade to 2.4GHz or 1.3GHz in the future for doing longer-range flights with more obstacles.
2. What radio gear to use?
My foray into FPV started with this cheap SkyZone transmitter and receiver set from HobbyKing. I used a 7″ LCD as my FPV monitor and a Boscam HD19 as my flight camera. The setup was a cheap introduction to FPV, but it was unreliable. Lots of radio interference made it hard for me to fly from the FPV view alone.
Today I use a FatShark 5.8GHz 250mW video transmitter with a SpiroNet Circular Polarized antenna to send video from my GoPro Hero 3 Black down to a pair of FatShark Dominator goggles with a Team Black Sheep 5.8GHz Dominator Receiver and the same SpiroNet CP antenna. Wow, lots of technical gear. I’ve tested this system out with fantastic results. I get crystal clear video in a 700 meter radius and it only starts getting fuzzy when I get out to 1 kilometer+. I can even fly behind smaller trees without too much interference. I’m about to start testing directional antennas to see what kind of improved range I can get without sacrificing convenience.
If you want a very inexpensive introduction to FPV, the cheap stuff will work. But if you are serious about the hobby it’s worth investing in some nice radios — they’re not much more expensive!
3. LCD Monitor VS FatShark Goggles?
Get a pair of FatShark goggles and never look back.
This weekend I started a Meetup Group: Fort Collins Drone Enthusiasts. Our first event was this evening – a fly session at City Park. Four people showed up, which I think was a pretty good turn out. We flew for a couple of hours.
Today I bought a deep cycle battery with 114Ah @ 12V and 1A discharge — so we got to charge in the field for the first time.
Here’s my favorite clip from the day
Today I hit a huge milestone in my personal exploration of drones. I tested a feature called ‘follow-me’ on my quadcopter’s flight controller that makes the copter fly after a specific device. In my case I used a Samsung Galaxy S3. My quadcopter followed me very smoothly as I ran a circle around a field. This is a huge step towards autonomous filming of any action sport. Very exciting! This video details my setup, and how everything worked.
I broke down and got the new GetFPV plug-and-play gimbal for my QAV400 quadcopter. The gimbal keeps my GoPro level and facing at the horizon, no matter how the quadcopter moves.
These are a few clips from my first gimbal flights. I haven’t done any tuning on the gimbal’s controller and the quadcopter is not tuned well right now – causing lots of fidgety movements during flight. I’m impressed with how well the gimbal corrects for them!
After flying the QAV250 micro quadcopter for several months I was lusting after something bigger and more stable. I settled on GetFPV‘s QAV400 since I’ve had such a good experience with the GetFPV store and with the QAV250 quadcopter frame.
Instead of using the OpenCC3D flight controller for my QAV400 (which I’ve used and loved on my 250), I opted to set the 400 up with a 3DRobotics ArduPilot Mega (APM) 2.6. I had the APM sitting on my shelf after using it for fixed-wing planes about 6 months ago, and really wanted to try an autopilot with a quadcopter.
I’ve spent the last week building and tuning my QAV400 with the APM 2.6, and it’s really stable now.
Today I flew my first autopilot mission, controlled almost exclusively using a Samsung Galaxy S3 phone (wow!). Check it out: