DJI FPV Video Quality Problems With Second Goggles

[BudWalker]

I am considering getting a 2nd set of Goggles for audience mode use.... is the telemetry also displayed on the 2nd set in audience mode?

Yes, the main screen in the primary and audience goggles are the same except that goggle recording time (in the upper right corner) is different. The goggle recording time in the primary goggles reflects the recording time for the primary goggles; likewise for the audience goggles. The sub screens are also different; e.g. the Transmission screen is where the choice of primary vs audience mode is made.

 

[prz3mk0]

Yes, the main screen in the primary and audience goggles are the same except that goggle recording time (in the upper right corner) is different. The goggle recording time in the primary goggles reflects the recording time for the primary goggles; likewise for the audience goggles. The sub screens are also different; e.g. the Transmission screen is where the choice of primary vs audience mode is made.

Thanks BudWalker! Short of getting the 2nd set of Googles is there any other way to get the telemetry out? I am guessing/thinking the only way would be to see it on a hardwired iPhone/mobile but that's not possible natively.... any idea if there's a parameter that controls that? Thanks!

 

[BudWalker]

Thanks BudWalker! Short of getting the 2nd set of Googles is there any other way to get the telemetry out? I am guessing/thinking the only way would be to see it on a hardwired iPhone/mobile but that's not possible natively.... any idea if there's a parameter that controls that? Thanks!

Not that I know of. The Fly App will display the camera view but it doesn't have the telemetry info (height, distance, battery, goggle and controller downlink signal strengths).

 

[prz3mk0]

BudWalker, thank you for all your help. One more thing I am wondering and you might know the answer: do the audience Googles need to be the same FW as master and AC to work? I stayed on 01.02.0000 for obvious reasons.

 

[BudWalker]

BudWalker, thank you for all your help. One more thing I am wondering and you might know the answer: do the audience Googles need to be the same FW as master and AC to work? I stayed on 01.02.0000 for obvious reasons.

I don't actually know but I suspect that they don't need to be on the same FW.

 

[prz3mk0]

I don't actually know but I suspect that they don't need to be on the same FW.

You're right - just tested today - they do not need to be on the same FW.

 

[Chaosrider@brilliantfrogs]

You can use WideFPV to access the video feed, but that requires a computer connected to the goggles via USB.

WideFPV

Watch and record DJI HD FPV video in superview

widefpv.com

The practical range for a USB cable is, IIRC, about 15 ft.

I suppose I could connect it to a laptop via USB, and then if I wanted to get really elaborate about it, I could connect a larger external monitor to the laptop.

Hmm...I actually have a laptop and a light 22" TV that I could use for this purpose.

Interesting!

Thx,

MM

 

[Chaosrider@brilliantfrogs]

Quite doable, done it.

Connect goggles via USB C to your phone, run DJI Fly on phone and display video feed. Share phone screen wirelessly with big screen, voila!

A cheap, weak processor low RAM phone may struggle, but my Z Fold 2 handles it like a champ.

So, there is a viable solution. Goes like this:

FPV goggles v2 –> phone w/DJI Fly via USB C cable –> share phone screen over wifi –> HDMI wifi screen mirroring dongle –> VR goggles with HDMI input

Here's a dongle that will do the trick:



Less than $15 at Walmart. The VR goggles won't be cheap, but much less than a second set of DJI FPV v2 goggles.

Interesting.

I'd very much want to know the quality of the final set of goggles using this Rube Goldberg set up?

Thx,

MM

 

[Chaosrider@brilliantfrogs]

I don't actually know but I suspect that they don't need to be on the same FW.

It might work, but IMNSHO, using components with different FW versions is asking for trouble.

MM

 

[rktman]

Interesting.

I'd very much want to know the quality of the final set of goggles using this Rube Goldberg set up?

Thx,

MM

Up to the goggles. Screen sharing happens at the resolution of the phone screen. What the target does with that is up to the target... In this case the dongle.

 

[Chaosrider@brilliantfrogs]

Up to the goggles. Screen sharing happens at the resolution of the phone screen. What the target does with that is up to the target... In this case the dongle.

OK, I think that helps...maybe...

I use a Samsung Galaxy S20 Note for flying my drones. That's unlikely to be the limiting factor.

Assume the second pair of goggles is another True Blue DJI pair of goggles, just like what comes in the box. In that event, will the video quality in the second (audience) set of goggles, be any lower than the video quality in the first (primary/control) set of goggles? And if so...why?

There have been a fair number of comments that the audience goggle video is lower quality than the primary goggle video, and some accompanying videos suggested that was the case. I was starting to get a better handle on this, when my DJI FPV purchase went on hold.

Now, with the Mini-3 specs out, it's starting to make more sense for my next drone to be the FPV, rather than the Mini-3. But I'd really like to understand this issue more completely than I do now.

Thx!

MM...FP..?

 

[Kilrah]

If you get a 2nd pair of DJI FPV Goggles then nothing that was said regarding the "hacked together" setup applies and the phone isn't part of the equation.

 

[Chaosrider@brilliantfrogs]

If you get a 2nd pair of DJI FPV Goggles then nothing that was said regarding the "hacked together" setup applies and the phone isn't part of the equation.

So, if I do get a second pair of DJI FPV goggles, what's the signal path from the drone to the second pair of goggles?

I just ordered my FPV today!



MM-FPV!

 

[prz3mk0]

So, if I do get a second pair of DJI FPV goggles, what's the signal path from the drone to the second pair of goggles?

I just ordered my FPV today!



MM-FPV!

AFAIK from reading the forum it is from the drone to the 2nd set of Googles, which is why sometimes there is a quality issue since the master set of Goggles is prioritized. Correct me if I am wrong.

 

[Chaosrider@brilliantfrogs]

AFAIK from reading the forum it is from the drone to the 2nd set of Googles, which is why sometimes there is a quality issue since the master set of Goggles is prioritized. Correct me if I am wrong.

I've never quite been able to sort this out.

If the drone is just transmitting, the signal quality shouldn't been impacted at all by how many goggles are receiving the transmission.

I seem to recall that the signal path is more complicated than that, and that there's some kind of linkage/authentication problem.

I have yet to find a clear answer on this. DJI support responded to my inquiry in a way that was internally consistent, but didn't seem to really address my question.

"If you can't explain it simply, you don't understand it well enough."

--Albert Einstein

Does anyone understand this well enough to explain it simply? I certainly don't, and I would very much like to!

Thx,

MM-FPV!

 

[Chaosrider@brilliantfrogs]

I'm going to check this out:

DJI FPV Deep Dive - Pilot Institute

pilotinstitute.com

MM-FPV!

 

[prz3mk0]

I've never quite been able to sort this out.

If the drone is just transmitting, the signal quality shouldn't been impacted at all by how many goggles are receiving the transmission.

I seem to recall that the signal path is more complicated than that, and that there's some kind of linkage/authentication problem.

I have yet to find a clear answer on this. DJI support responded to my inquiry in a way that was internally consistent, but didn't seem to really address my question.

"If you can't explain it simply, you don't understand it well enough."

--Albert Einstein

Does anyone understand this well enough to explain it simply? I certainly don't, and I would very much like to!

Thx,

MM-FPV!

I admit I don't understand it well enough, again, this is just from reading the forum, and as far as I recall it was not explained in details, except for the picture issues on the 2nd set.

Wild guess, maybe the master set does ACK (similar to IP network) to the drone and the slaves do not. This would make sense since presumably the pilot is wearing the master set. In other words, the master set would always have the perfect picture because the transmission errors would be corrected. Drone wouldn't care about correcting the transmission errors to the slave sets, since they wouldn't acknowledge receiving proper signal at all.

Edited for thought clarity.

 

[Kilrah]

That has been mentioned by others indeed in addition to what was already talked about. The aircraft and goggles are on a network, if the goggles drop a packet they will ask the aircraft to resend it. The audience goggles can only listen so if they drop a packet they can't ask for a retransmit and have to deal with some corruption.

Does anyone understand this well enough to explain it simply?

Nobody can understand it 100% since only DJI know exactly how it works but they'll never tell. You'll never get more than educated guesses.

Doesn't really matter in the end. We know how it behaves and that's just how it is.

 

[Chaosrider@brilliantfrogs]

I admit I don't understand it well enough, again, this is just from reading the forum, and as far as I recall it was not explained in details, except for the picture issues on the 2nd set.

Wild guess, maybe the master set does ACK (similar to IP network) to the drone and the slaves do not. This would make sense since presumably the pilot is wearing the master set. In other words, the master set would always have the perfect picture because the transmission errors would be corrected. Drone wouldn't care about correcting the transmission errors to the slave sets, since they wouldn't acknowledge receiving proper signal at all.

Edited for thought clarity.

I'm part way through the Pilot Institute DJI FPV course, and I finally got some clarity on this.

The audience pair of goggles gets it's signal from the pilot goggles, and not from the aircraft. That certainly presents opportunities for signal lameness. Back when I was integrating large computer systems, I coined the cynical phrase "Interfaces = Death". That goggle signal architecture adds an interface. That choice of interface architecture is apparently driven by some kind of linkage/security consideration, although it's not obvious to me why there wouldn't be a simple encryption-based solution that would fix that without signal degradation.

I uncovered some of this in my "pre-purchase" FPV research phase, but now that I actually have one coming, it's served to focus my attention more sharply! I understand it a bit better now.

Thx!

MM-FPV!

 

[Chaosrider@brilliantfrogs]

That has been mentioned by others indeed in addition to what was already talked about. The aircraft and goggles are on a network, if the goggles drop a packet they will ask the aircraft to resend it. The audience goggles can only listen so if they drop a packet they can't ask for a retransmit and have to deal with some corruption.


Nobody can understand it 100% since only DJI know exactly how it works but they'll never tell. You'll never get more than educated guesses.

Doesn't really matter in the end. We know how it behaves and that's just how it is.

Matters to me! I've always liked to understand how things work.

The more I poke at it, the more I'll understand it.

Of course, to really understand it, I'll need to get the second set of goggles, so that I can play with them directly...



MM-FPV!