Discussion Beta85 ELRS quad and General Discussion Thread

[Pathfinder075]

In case anyone is looking for rates/settings for a Tiny Whoop or Whoop, for FPV Freerider Recharged (or Classic), try these (for a Mobula7). Found at the FPVFreerider Community link below.

https://itch.io/t/175047/tiny-whoop-or-i...playground

Code:

Mass 0.6
Gravity 30
Drag 0.8
Angular Drag 28.2
Angle 40
FOV 85
Throttle 60
Yaw 403
Pitch/Roll 363
Expo 0.35
Super Expo 0.5

[Pathfinder075]

So new question. Is their anything I need to consider before flashing BlueJay? I came across a Joshua Bardwell video on it and remembered Lemonyleprosy had mentioned it long ago when i first bought the drone. I found an entry at https://github.com/mathiasvr/bluejay/wik...d-Hardware that suggests it will work on my FC.

So I will probably have a go at doing it tomorrow night.

[Lemonyleprosy]

It’s pretty straightforward.
Make sure you have a battery plugged in.
Do it from the esc-configurator.com website.

Choose 48khz for your pwm frequency.
Don’t freak out like I did if it makes different tones the next time you plug it in.

[Pathfinder075]

Cheers Lemony.

All being well it will get done tonight.

On the tones side, I want to change them anyway, maybe the Mario powerup sound that a lot of people use.

[Pathfinder075]

Still trying to work out why the camera blew up. It only seemed to happen a couple of flights after I changed the VTX from 200mw to 350mw, although it is probably just a coincidence. I checked the solders on every pad and they seem fine, checked the connectors for loose wires, couldn't find anything obvious. So I ordered another Caddx Ant Nano 4:3 and hopefully that will bring everything back online. Also bought a Twig XL frame for another project, but that will be a different thread.

I will update as and when I can. I do want to try and work out why this camera died or if it has fully died, but I don't have a spare vtx at present to plug it into for testing purposes.

A side question: Is it possible to just connect a cam into a VTX without running it through a FC, ie, can you output video from a separate camera through a different VTX board on a different channel? It's a question I've had for a while, ever since iFly started his Rescue Quad thread. I know he uses a board with twin cam inputs and switches between them. But would it be possible to just use a separate cam and VTX and ignore the FC (program channels via a different route)? Or would you need to run a small FC and only connect the VTX through it (but nothing else)? I wondered if I could do it via say an OpenVTX board and program the board directly or hack the source to force video to transmit on a specific channel.

[SnowLeopardFPV]

A side question:  Is it possible to just connect a cam into a VTX without running it through a FC, ie, can you output video from a separate camera through a different VTX board on a different channel?  It's a question I've had for a while, ever since iFly started his Rescue Quad thread.  I know he uses a board with twin cam inputs and switches between them.  But would it be possible to just use a separate cam and VTX and ignore the FC (program channels via a different route)?  Or would you need to run a small FC and only connect the VTX through it (but nothing else)?  I wondered if I could do it via say an OpenVTX board and program the board directly or hack the source to force video to transmit on a specific channel.

Yes you can do that but if you're specifically talking about running two VTX's on the same quad then you will likely run into severe interference issues with one of them trying to drown the other out even if they are broadcasting on different channels.

[Pathfinder075]

Could you mix Digital and Analogue or HDZero and Analogue on the same drone to overcome the issue?

[SnowLeopardFPV]

I've seen a few people try it on wings where you can get a greater separation of the two VTX's but the results haven't been that good TBH. On a quad you have even less real estate to separate the two VTX's so it will probably be even worse. I've not seen anyone try doing it on a quad.

[Pathfinder075]

It's to be a future project I guess.

I need to work out how to separate the transmissions. I did wonder whether you could run a standard omni for the analogue and use a helical antenna for the other, then mount one on the top and one on the bottom.

Thanks for the help, SnowLeopard.

[Lemonyleprosy]

You could try to minimize that interference by making sure that they were each transmitting on separate channels with no overlap, and put a RHCP antenna on one vtx and a LHCP on the other vtx.

It’d also require two separate vrx’s with antennas to match whichever vtx it was receiving. You wouldn’t be able to switch camera views in flight unless you ran them to separate monitors/screens so that you could just look at whichever you wanted.

You’d probably still get some interference.

If you just want to be able to record video from two different camera angles throughout the flight with no switching, etc-
You could just wire the second camera directly to an onboard dvr module and not use a vtx for it. That would record the entire flight from the second camera, and you could record the video from your main in flight cam through your goggles if they have that ability.

Another option- I believe there is/was some camera modules and goggle that are capable of 3d/stereoscopic imaging. If you had both, you could potentially hack apart the camera module so that you can move the second camera to wherever you wanted and then just close one eye depending on which video feed you wanted to see. Not really a practical option, but a fun theory/thought experiment.

You could potentially put them on completely different frequency spectrums- ie: one vtx on 1.2/1.3ghz, the other on 5.8ghz. But, I think 1.2ghz can interfere with a 2.4ghz radio link. I’m guessing 2.4ghz doesn’t interfere with 5.8ghz, or we would have serious issues using 5.8ghz video with a 2.4ghz radio. So maybe, 900mhz for your radio link, 2.4ghz for one cam, 5.8ghz for the other?

I’m guessing that this will have a practical use- ie: one person flying the quad while another is looking down at the tree canopy to look for hazards and whatnot. If that’s the case, then I’m also assuming weight wouldn’t be an issue since it would be used for commercial purposes- so that last suggestion of putting them on completely different parts of the frequency spectrum may be the best solution, as long as nothing interferes with anything else, and sending each vrx signal to separate monitors. I’m not an electronic or radio engineer, so I can’t tell you if it would actually work with good video via both transmissions, and without either video signal or your radio link interfering with each other.

[Pathfinder075]

It's kind of part of an idea of having a drone that can be flown by a person, but with a second feed from a camera mounted on the underside. So for my own example, you are doing say a survey of a section of a forest looking for disease hotspots. You would have a pilot that can fly the drone using a cheap analogue feed. You would then use the second, better quality feed for your disease specialist to look at the actual forest below. An onboard DVR option is also an option. Using something else radio band wise is similarly not out of the question. That RubyFPV framework interests me since the latency on the feed isn't a massive concern if the person viewing the second camera isn't flying the drone.

The main thing for me is the drone has to be cheaper than equivalent commercial offerings. Easily repairable using over the counter components. Buildable and repairable in the field. So use say a standard 5" or 6" frame, with Li-ion or Lipo for power, a standard motor and prop that could be bought at any RC shop that caters for our side of the hobby.

Right now you can buy big buck commercial kit, but for a smaller operation they probably don't need that 10k drone, nor may be able to afford it. A 5" or 6" drone with a standard and bottom mounted camera that can be put in the air easily and quickly, flown by one member of the team while the others view from the second feed would be a much cheaper solution.

Don't know how I deviated this thread again, but LOL.

[Lemonyleprosy]

I think it could be fairly easily done for well under $1k, I’m just unsure about interference.

5” to 7” frame, 915mhz ELRS for radio link, 2.4ghz for pilot video, 5.8ghz for Ruby or openHD.

I don’t *think* 915mhz would interfere with 2.4ghz or 5.8ghz.
If it was me, I’d just start acquiring bits and testing. I’d start by building a ruby or openHD setup, and then seeing if it obliterated my 2.4ghz control signal.

Actually, I think Ruby and openHD can also use 5.8ghz for the control link as well as long as you build a controller- so yeah, I’d start with Ruby, build the video and control system, and then just get a 2.4ghz vtx and vrx for the pilot video, cross my fingers, and see what happens.
5.8ghz- Ruby and control. 2.4ghz- pilot video. If that didn’t work- maybe 5.8ghz Ruby and control, 1.2/1.3ghz pilot video.

Wonder how it would work out. Antenna choice and placement would be important.

Edit- apparently 1.2ghz can interfere with 900mhz, gps, and 2.4ghz- so maybe not 1.2ghz.
https://oscarliang.com/1-2ghz-fpv-guide/

[Pathfinder075]

900MHz ELRS might be a possibility for the control end, then 5.8 for the pilot video and maybe 2.4 or 802.11b/g for the remote viewers.

I would probably test different antenna placements, but could see one VTX aerial pointing up and the other pointing down, and/or one of them being a helical or patch type. Your idea of using LHCP or RHCP interests me too. But i think the problem is still the amount of power being output.

[iFly4rotors]

I have been watching this thread...so...

I can't say for sure, but the LHCP  and RHCP might be something to try, however,
I do think that you get quite a bit of interference with the higher VTX settings.

Pretty much all the VTXs that I have seen are 5.8. 
So, where do you get the 2.4 or 802.11b VTXs ?? and monitors ??

Now, I don't do digital, but what frequency does DJI systems use for video??

If it is just about being physically separated...then what about a long mounting
platform, like an outrigger, on each side. Yeah, it would have the appearance
of a wing with very long and tiny wings (ha, ha). Anyway, just a thought.

I am also guessing that this will NOT be a sub-250 gram build by the time that
you get everything in there and have motors big enough to fly and be stable,
and battery pack large enough for some decent time and range. 

When do plan to start this build???

[Lemonyleprosy]

FuriousFPV has 2.4ghz goggle modules and vtx. ImmersionRC has a 2.4ghz vrx that is more of a external type module. The monitors could be any type of battery powered display with an hdmi or video in port, just have to route the output of the vrx to it.

As far as 802.11, that would be diy- Ruby or openHD.

Oscar did a review on the FuriousFPV 2.4ghz vrx & vtx:
https://oscarliang.com/2-4ghz-fpv-furiousfpv-true-d/