Hi,

This isn't one of those yet-another-thread-about-HD-FPV-downlink-and-why-it-can't-be-done, this is the actual thread about a working system that I have developed.

My main motivation for this project was that I loved that high resolution feel of various recorded HD FPV videos with cameras like GoPro, etc. You can of course watch this only after you flew... because your real time analog camera video is blurry, with bad colors, generally bad. Now, if I could somehow have this high quality feel in real time, right on the screen or in the video glasses (and not costing $3000) wouldn't that be great? Now, I can!

Lets start directly with a video of how it actually looks and behaves (ground range test):

HD FPV Downlink - Ground Range Test (3 min 53 sec)

Youtube lowers quality a lot, it's a lot less sharper than the original, so I have included some screenshots of the raw video.

This ground test is somewhat limited. For example, there's barely a line of sight (trees cut into Fresnel zone a lot) and the radar from the nearby airport seems to blind receivers at every turn it makes (every 3.8s), resulting in gray blocks (= packet loss) visible in the video. Even with these problems, it still provides usable video feed, no frame freezing or similar problems.

The most important feature for FPV I think is the fail-safe video feed, which provides a low quality video when the HD signal goes out of range. Video does not suddenly stop when it goes out of rage like you would expect from a digital system, it transitions to a low quality video, which still allows you to retain control. It has a gain of about 4dBm over HD signal, so its range is theoretically 1.5x of the HD signal.

The transmitter + camera are small (and light) enough to fit Easystar.

Now, because this isn't analog anymore, it needs a computer to display the video. The laptop doesn't need to be very powerful, it just should have at least a dual core CPU. I have tested it on some old Core 2 duo 1.86GHz and it ran just fine. It didn't run very well on a netbook with a dual core Atom CPU, it skipped frames. You can connect video glasses directly to laptop and watch the video stream.

Obviously, there is no OSD support yet. This link can of course be used to stream digital data from some OSD product via RS232 or audio link, which would be displayed in the receiving application, but this option has not been explored yet.

Audio will be supported later, priority is on video right now. It could provide stereo digital audio, there's plenty of spare bandwidth for that.


I am now looking for some suggestions what should I do next with this project. I was thinking about open sourcing it as DIY project.



Here is some basic info about this project:
- 2.4GHz band
- Video:

Aspect ratio: 16:9
Normal mode (HD) 1024x576 @ 30fps
Fail-safe mode (FS) 320x192 @ 10fps
FS mode is activated when HD signal goes out of range
Field of view: 90+ degrees, sharp wide angle lens, minimum distortion
Latency: ~170ms

- Audio: digital stereo tested, not yet implemented
- Range:

To be determined
Ground tests indicate (at 100mW TX power, 2dBi antennas on RX and TX):
~1.6 km (~1 mile) for HD video
2.3+ km (1.43+ miles) for FS video

- Transmitter

Consists of main board and camera connected with cable
Default TX power 100mW, up to ~400mW
Power consumption: ~8W (TX @ 100mW), Vin: 8-20V
Main board size: 95x65x30mm, light
Camera size: 100x46x46mm, <100g

- Receiver:

Laptop (notebook) needed with dual core CPU, the faster, the better, currently tested only on Windows (XP ... W7, 32 and 64bit), uses multiplatform libraries - should work on Mac, Linux, ...
Java application displays video, RX information and records video to HDD
Signal receivers are USB adapters
Diversity: up to 4 independent receivers can be used

- Targeted for RTH equipped machines only
- Uses off-the-shelf hardware, no custom hardware (besides cabling)

reserved space

pretty cool, but for myself I can't see any practical use for it. I use 8 and 10" haier on the ground and the last thing I am thinking about is how clearly I can see the leaves in the tree I just missed crashing into.. My 540 fpv cam provides a plenty sharp enough image, as does the gopro when I use it for VDL. I am more worried about where I am going and framing for my final product than I am how clear the picture is, but that's just me.

However, I can see a use for this if I was flying around my yard with my quad and wanted to sit inside somehow and fly using my 50" plasma, that would be very cool! Buy why are you limited to using a laptop for the video? Being restricted to a small screen almost defeats the purpose of HD, does it not?

Anyway, great work and I love seeing the new innovations people come up with, will be watching with interest!

Originally Posted by Glenstr

pretty cool, but for myself I can't see any practical use for it. I use 8 and 10" haier on the ground and the last thing I am thinking about is how clearly I can see the leaves in the tree I just missed crashing into.. My 540 fpv cam provides a plenty sharp enough image, as does the gopro when I use it for VDL. I am more worried about where I am going and framing for my final product than I am how clear the picture is, but that's just me.

However, I can see a use for this if I was flying around my yard with my quad and wanted to sit inside somehow and fly using my 50" plasma, that would be very cool! Buy why are you limited to using a laptop for the video? Being restricted to a small screen almost defeats the purpose of HD, does it not?

Anyway, great work and I love seeing the new innovations people come up with, will be watching with interest!

This is targeted mostly for people who fly for the fun of it and want to have the best image quality on the ground in real time. Of course, you don't need this for AP, analog as a preview when you're shooting pictures with camera is enough.

Laptop is needed to decode the video, you can then display it using your laptop's HDMI or DSUB on whatever you like (TV, video glasses, ...).

Which camera do you use for this? How do you pickup the HD signal?

Very interesting project.

Try with 500mw-1W power because that's the power consumption we are used to.

Any pictures from the hardware?

Thats more 16x9 format that HD. HD starts around 720 V lines and up. Looks great though

What module are you using? Is it full duplex?

Interesting.

Can you make a video filiming the laptop screen and what the camera is seeing in the same shot so we can see if latency would be an issue?

In the range test video you made was tx and antenna inside the car or mounted outside?

Moe

Wow, this sounds amazing! HD fpv is definitely the future. I look forward to more info.

This is a promising project but most people dont want to use a laptop so if some sort of module designed for the HD processing was manufactured that would be preffered. I personally dont like to use laptops for FPV because I have enough stuff to carry on the field and I would rather prefer taking boot up times and the potential for software for crashing to be eliminated out of the equation.

Also please take some pics of your setup.

This looks pretty cool.

I will echo malcr001....... and say, find a way to ditch the laptop.

A dedicated module for the HD processing would be preffered.

From the video it looks like the view is plenty wide. Nice!

Thanks for showing this.

Please show us pics of the camera and other gear. (vid Tx etc...)

Great project! That's what I am waiting for, it's a big step ahead.

Hope it will be available soon. I can't wait for this Tx (plus the Sony or Zeiss Oled HD glasses)...

latency could be lower and the gray stuff could be filtered out :-)

i agree, for practical use by the everyday FPV'r, a dedicated system without a laptop is best.

However, depending on price, i'd prolly still buy it and use a laptop in teh mean time. obviously this is an emerging technology on the hobby level.

also, 500mw would prolly be the minimum IMHO.

great stuff!