ST16 Video Latency & DJI's new Controller

[CAPTAINDRONE]

I was asked on the Phantom forum if I could post a video regarding the video latency of the new DJI Phantom 4 controller. DJI is telling everyone that their new controller has minimal video lag.

DJI is entering an area that Yuneec has had for awhile now, which is integrating the screen with the controller. Unfortunately, this is a new area for DJI so they have made the Android system somewhat closed to the user. To me, this is a problem because:

- You can't add 3rd party Apps or any Apps for that matter.
- If the DJI App crashes while flying you essentially have to turn off the controller and then back on and hope your drone has not flown away (especially if you were flying in non-GPS mode).

The ST16 has none of the above issues for me.

Oh well... DJI will have to figure out solutions as they move forward in this area.

VIDEO LATENCY. When I did a simple video latency test on the new DJI controller I also included the Yuneec ST16 controller. Some feel the ST16 has plenty of video lag, but I've never noticed it. I find it perfect for everyday flying in tight situations.

In the days of the Phantom 2 & 3 I've used tablets that had a video lag of 1.5 seconds which at the time was considered really good. Today, people are most happy when the video lag is no more than 1 second. So when you get down to less than half a second, that is really good & makes flying effortless & responsive.

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[Rayray]

Neat! An elegant solution that is at once simple yet precise. Thanks for sharing, CD.
I have 3 TH's, all built at different times, all with latest firmware. Latency on all three is so small it is not noticeable.

 

[PatR]

It's great to see DJI finally stepping up with an included video screen. It appears they were paying attention to many that bought an H because they didn't also have to buy another pad or phone. The screen is a little small at 5.5" but much better than having to purchase a second device or tie up your phone when flying, or have your phone linked to a WiFi network that has the potential to review and/or download the contents of your phone while connected to the aircraft. The DJI Go App is incorporated into the Phantom 4 screen.

1/4 second latency is pretty good by any standard, as is 1/3 second. One of the worst systems for latency I've ever used is resident with the Chroma and Typhoon 500 systems. Depending on the distance it can seem like well over a second. The worst latency I've ever encountered was related to a military drone where control response could be up to 2.5 seconds behind the control input in manual control mode.

I've only used the H out to 1,000' but in over 200 flights I have yet to experience latency that provided any concerns or difficulty related to command and control. Overall I think what we have available to us in consumer drone packaging is working out pretty well. None of them can quite match what can be done with a custom built system but the custom builts cost a lot more than a consumer level buyer is willing to pay, or deal with the time and labor required for a build.

 

[BillyTexas]

Dji charges about 300 extra dollars for that built in screen.

Bill W.

 

[CAPTAINDRONE]

It's great to see DJI finally stepping up with an included video screen. It appears they were paying attention to many that bought an H because they didn't also have to buy another pad or phone. The screen is a little small at 5.5" but much better than having to purchase a second device or tie up your phone when flying, or have your phone linked to a WiFi network that has the potential to review and/or download the contents of your phone while connected to the aircraft. The DJI Go App is incorporated into the Phantom 4 screen.

1/4 second latency is pretty good by any standard, as is 1/3 second. One of the worst systems for latency I've ever used is resident with the Chroma and Typhoon 500 systems. Depending on the distance it can seem like well over a second. The worst latency I've ever encountered was related to a military drone where control response could be up to 2.5 seconds behind the control input in manual control mode.

I've only used the H out to 1,000' but in over 200 flights I have yet to experience latency that provided any concerns or difficulty related to command and control. Overall I think what we have available to us in consumer drone packaging is working out pretty well. None of them can quite match what can be done with a custom built system but the custom builts cost a lot more than a consumer level buyer is willing to pay, or deal with the time and labor required for a build.

Consumer drones have come a long way in a short period of time. DJI does have a new controller coming out very soon called the "CRYSTALSKY". It is super bright, larger display and supposed to have .18 seconds of latency. Honestly, when you get below .5 seconds of latency, for us older guys, does it really make a difference?

 

[CAPTAINDRONE]

Dji charges about 300 extra dollars for that built in screen.

Bill W.

I do find that price to be a bit high. Sure you can view it in bright sunlight due to how the screen is designed (sunshades no longer required). But is that worth $300? And it's only $300 if you buy the bundle with the P4P. If you buy it alone, it sells for $600! I think DJI adds the high price because they add such items to the controller as the high visibility display, HDMI port, built in WiFi, built in GPS, Micro SD Card and of course their modified version of ANDROID to run the DJI GO App on.

BUT WAIT... Yuneec includes a 7" tablet in the controller and tosses in everything the DJI controller has and more. Sure it's not high visibility, but I've had no problems using it on sunny days.

DJI has an even newer controller with built in display about to hit the market. The new controller is designed to work with most DJI drones from the past year & forward. It's called CRYSTALSKY and it's designed for the elements (outdoors). The price? My guess is $800 to $1200 just for the controller (depending on screen size).

 

[PatR]

$475.00 for an ST-16 from Yuneec via Amazon.

As for latency under 0.5 seconds, for those that fly LOS it's not all that much of a deal unless you fly so close to the subject matter you have to rely on object avoidance systems to prevent running into things. Essentially, incredibly low latency is most useful for those that elect to fly in a manner that can be quickly and easily defined "unsafe" in a legal proceeding. I fear the time of those proceedings is on our door step.

 

[WesBur13]

Heres my test I just did to figure the latency for the ST16

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[dotsi]

Great tests, but they are static and they do not account for distance or movement.
Latency becomes greater as the signal gets weaker or gets distorted. In a normal environment where the position of the drone is changing all the time the latency and/or fps fluctuates grately. The average latency might be under 0.5s but it is still not suitable for FPV flying.
Just when you are trying to pass between those trees the frame rate drops to 1 fps and you crash before you see the branch.
I guess this is why DJI is producing controllers with 7km range now. So at 500m where normal flying happens the signal is super strong and latency stays manageable.
At just 10m/s, the 0.3 latency you measured is 3m, and then there is your reaction time and latency again to pass the control signal. Even if you can see the branch from 10m away on your screen it could be too late with all latencies combined. Imagine driving a car with 0.3s latency. It is already a small number but it needs to get down to 0,03s for digital FPV.

 

[Tuna]

Great tests, but they are static and they do not account for distance or movement.
Latency becomes greater as the signal gets weaker or gets distorted. In a normal environment where the position of the drone is changing all the time the latency and/or fps fluctuates grately. The average latency might be under 0.5s but it is still not suitable for FPV flying.
Just when you are trying to pass between those trees the frame rate drops to 1 fps and you crash before you see the branch.
I guess this is why DJI is producing controllers with 7km range now. So at 500m where normal flying happens the signal is super strong and latency stays manageable.
At just 10m/s, the 0.3 latency you measured is 3m, and then there is your reaction time and latency again to pass the control signal. Even if you can see the branch from 10m away on your screen it could be too late with all latencies combined. Imagine driving a car with 0.3s latency. It is already a small number but it needs to get down to 0,03s for digital FPV.

Agreed.

Has anyone measured the effective stopping distance at 10m/s? Neither this nor the DJI kit can be compared with current FPV drones which are heading off in a different technological direction (and very quickly, too). Regardless (by law) you shouldn't be relying on FPV to fly any current drone.

Realistically, it's a huge risk to be within 10m of most obstructions, and flying at 22mph (10m/s) close to trees is only going to end one way.

It doesn't help that a lot of bloggers repeat the DJI press information without applying any critical thought, or checking whether the figures they quote make any practical difference. It's only now that we're beginning to see people openly saying that the Mavic isn't that fast, isn't that stable and has a disappointing camera. As it is, standard drone latency is (just about) good enough to let you fly without being completely disorienting, but certainly not good enough to rely on in close spaces. That's fine though - if you wanted an FPV drone and bought a Typhoon, you really should have done your homework more carefully

What's reassuring is that the Typhoon link isn't inherently 'slow'. It tests in the same class as the latest drones, which is not bad considering how hard the companies are working on new advancements.

 

[JohnL]

Agreed.
<snip>
It doesn't help that a lot of bloggers repeat the DJI press information without applying any critical thought, or checking whether the figures they quote make any practical difference.

Clear and precise observation. It appears to me that the majority of the Vlogger clowns I run across on YouTube are completely unaware of the concept of critical thought. It's obvious they're in it for the money and NOT the love of technology. Pretty pathetic IMHO.
Happy Holidays.