DJI Air 3 : Minor Airspeed Anomalies in Waypoint Mission Translated from Litchi Hub with Hub Bridge

[Mad_Pup]

After much wailing and gnashing of teeth, I was finally able to get Litchi Mission Hub Bridge to overwrite a short “template” waypoint mission in DJI Fly in my iPad, with a 99-waypoint mission created with the new Litchi Mission Hub on my Dell laptop.

To test the precision of the waypoint mission transcription process from Litchi Mission Hub to DJI Fly using the Hub Bridge, I created a convoluted spider’s web-shaped waypoint mission that took the drone 27 minutes, flown at 26.8 mph, to cover the total 11-mile distance, after launching the Air 3 with 100% battery, then landing it after the 27-minute journey with 20% battery.

While the shape of the flight path and the fixed 180-foot altitude made it through the translation process unchanged, I did notice at the start of two separate test flights of the same mission, that the global mission speed that I set at 29 mph had been unexpectedly altered following the translation process, from the specified 29 mph, down to 5.6 mph, which apparently is the Air 3’s “default” speed unless otherwise specified.

On yet another flight test of the same mission, the globally set airspeed that appeared in DJI Fly had been changed from the 29 mph, to 26.8 mph, which I initially assumed might be the maximum permissible speed for the Air 3 when flying fully autonomous waypoint missions. But then, when I looked up the maximum allowable cruise speed for the Air 3 while flying waypoint missions, a speed of over 30 mph was quoted.

While this second observed airspeed anomaly wasn’t as pronounced as the first one in which the pre-set 29 mph waypoint mission airspeed that was assigned in Litchi Mission Hub became just 5.6 mph in DJI Fly, I still decided to mention the speed discrepancy, small though it may be.

Finally, I found that when I tried to modify the DJI Fly waypoint mission global speed using that slider at the bottom of the screen, the speed could not be changed manually, yet oddly the speed increased to 26.8 mph after I shut down my iPad and restarted it before reopening DJI Fly.. I restarted the iPad because I found that pressing the green “Go” tab to the lower right of the DJI Fly screen did not start off the waypoint mission until I did a restart of the iPad.

While these inconsistencies are minor and manually correctable after a fashion, I still decided to mention them in case they are symptomatic of a bug that might still be traceable. All told I am elated to be able at long last to send my Air 3 on long waypoint missions created in Litchi Mission Hub, and my hat is off to the creators of the Litchi Mission Hub Bridge that puts the waypoint mission copy process within the reach of people with sub-par computer skills like me.

[Mike_M]

Hi Mad_Pup. I’ll try to help a bit with some info regarding speed. The Max speed you set is like a speed limit and more than likely will never maintain that speed during the entire mission. Speed is always reduced during curved corners, turns in order to stay on the path. With the screenshot you sent it makes sense the speed will be reduced while flying the mission. You are correct that the Max speed can only be set to 26.8 which is what DJI’s firmware allows with waypoint missions. So regardless of what speed you set when using any app the Max for DJI Waypoints is 26.8 and the speed will vary depending on a few factors. Also any conversion from a third party app to a DJI Waypoints mission will never be a one to one conversion. Hope that helps.

[Mad_Pup]

Thanks for taking a moment to shed some light on the airspeed fluctuations that I observed after the transposition of waypoint missions using the Mission Hub Bridge, Mike. The reduction of the airspeed down to 5.6 mph was the one that threw me, but it is possible that I touched the screen of my iPad without realizing it.

The key variables of altitude and camera orientation remained faithful to their original values after waypoint missions from Litchi Mission Hub were flown with DJI Fly, and that precision eliminated my primary concern about in-flight surprises occurring;

All told, I am delighted with Litchi Mission Hub Bridge, and it has enabled me to finally put my Air 3 to daily use. DJI’s native waypoint creating facility leaves much to be desired, so until the Hub Bridge was released, my Air 3 gathered dust, despite its impressive performance potential.

[Mad_Pup]

I just stumbled on a follow-up question that I must ask about POI markers that I placed in a saved Litchi Mission Hub waypoint flight. There were four POIs in one of the flight plans I created on the Mission Hub, but when I copied that flight into DJI Fly on my iPad with the Hub Bridge, the POIs are no longer visible on the DJI Fly waypoint flight path screen.

Being hobbled by my lack of knowledge about editing and re-saving DJI Fly waypoint flight plans to include the missing POIs, I am hoping to learn from more experienced users of the Hub Bridge, if there might be a workaround solution that will allow POIs created in Litchi Mission Hub to be replicated in their original positions after saved flight plans are copied to DJI Fly.

What I’ve discovered thus far is that Litchi waypoint flights that contain POIs will not replicate those POIs in DJI Fly screen of my iPad, after the Hub Bridge copying process. Also when I tried to launch the drone to fly an overwritten waypoint mission that previously contained POIs, an error message appeared when I hit the “Go” button, and the drone would not take off..

Acting on a hunch that transposing POIs from the new Litchi Mission Hub to the DJI Fly screen of my iPad might for now remain an unresolved issue, I deleted all POIs, but was unsure about how those deletions would affect the direction faced by the camera as the drone flew its path.

The deletion of the POIs before copying the flight plan from Litchi to DJI Fly did get rid of the error message and allow the drone to launch on the mission, BUT, the camera directions went haywire and I also lost control of the gimbal tilt, which I generally leave at -21 degrees. The gimbal remained at zero degrees for the whole flight, and my use of the thumb wheel had no effect on that fixed gimbal tilt angle.

Any thoughts on how I can resolve this new puzzle would be appreciated. In the meantime I will create a new mission in Litchi Mission Hub that entails no POIs, such that I’ll manually set the camera direction at each waypoint. I am hoping to see the erratic camera direction issue addressed in this way.

[Mad_Pup]

The new Litchi Mission Hub took some getting used to, but now that I’ve got the hang of its rudiments, I can see already it is a major evolutionary improvement on the original. I just found that if I set the both the gimbal tilt and gimbal pan to “manual”, the need for POIs goes away because that depiction of camera direction makes it a snap to adjust the camera direction (drone heading) to keep the camera’s field of view precisely where I want it.

[wesbarris]

@Mad_Pup

I did notice at the start of two separate test flights of the same mission, that the global mission speed that I set at 29 mph had been unexpectedly altered following the translation process, from the specified 29 mph, down to 5.6 mph

I think there is an anomaly here. In both Litchi’s Mission Hub and DJI Fly, one is able to set these two speeds:

• Global speed
• Waypoint speed (the speed at a waypoint)

I have found that even though the global speed my be correctly stored in the KMZ file (globalTransitionalSpeed), when loaded into DJI Fly, that global speed is ignored in favor of whatever the global speed slider happened to be set at in DJI Fly.

You can test this by transferring various missions from Litchi’s Mission Hub to DJI Fly. When the mission is opened in DJI Fly and then the global parameters of that mission are viewed by selecting the three dots (…) and looking at “Global Speed”.

The results I am seeing are inconsistent. You should test to verify this.

[wesbarris]

@Mad_Pup

There were four POIs in one of the flight plans I created on the Mission Hub, but when I copied that flight into DJI Fly on my iPad with the Hub Bridge, the POIs are no longer visible on the DJI Fly waypoint flight path screen.

If you have POIs in a mission but no waypoint references those POIs, they will not be transferred to DJI Fly. In order for the POIs to appear in DJI Fly, the “Waypoint Heading Mode” at the waypoints must be set to “Point of Interest”.

[Mad_Pup]

It is reassuring to hear confirmation from you, Wes, that the speed translation issue is not due to a unique computer issue that others might not be seeing. When I imported several different Litchi waypoint missions into DJI Fly, I noted that the speed assigned by DJI Fly for the mission did not always conform with the speeds I assigned in Litchi.

Since I know to check the speed after each waypoint file overwrite into DJI Fly, it is no trouble at all to reset the speed to the maximum allowable 26.8 mph, and then re-save the flight before takeoff. On a tangential note, my new all-time favorite budget DJI drone is now officially the Air 3, which has dethroned the mighty Mavic 2 Pro that I never thought I’d relegate to second best. The signal reach of the Air 3 is phenomenal, and its zoom capability is proving enormously useful for my security patrol surveillance missions out here in the sticks.

I thank you kindly for the missing jigsaw piece that I needed to ensure that the POIs are retained in DJI Fly. Over and out for now. Dusk is setting in and the Monkey King has just bellowed out his closing remarks of the day from the forest nearby. More drone adventures when day breaks.

[Mad_Pup]

Not long after daybreak I launched my trusty Air 3 on a 12-mile round-trip waypoint mission that was created on Litchi Mission Hub without the inclusion of any POI’s and with the camera gimbal pan (yaw) and tilt set to 'manual".

The spider’s web flight path, comprising 85 waypoints flown at 158 feet AGL and 26.8mph, took the drone 26 minutes to complete, before the drone’s landing within two inches of it’s launch spot, and with a surprising 29% of battery power left.

This flight was partly to test the Litchi Mission Hub Bridge, but also to record the capers of a few outlaws that have been stripping the metal fixtures from an abandoned hospital located about a mile from my lair. My friends in the regional vigilante force are always eager to engage in a little plinking practice, and the last time I alerted them to the presence of the looters who accessed the hospital grounds via a gaping hole they broke in the perimeter wall, events took a turn for the worse, from the burglar’s perspective.

Here a couple of the scrap metal prospectors can be seen spiriting away their haul for the day, evidently without a care in the world about previous skirmishes that occurred there.

All told I have been seriously impressed by the Air 3’s performance. This entire recon mission was flown fully autonomously, and the drone returned to base for a landing that can best be described as surgically precise. The Air 3 checks all the boxes that matter to me, without question.

Finally, if the Air 3 can cover 12 miles round-trip and land with 29% battery, then this amazing drone can likely fly round trips of 14 miles before landing with between 15 and 20% battery. That is a jaw-dropping range obtainable with stock batteries, though I plan to up the ante soon, and acquire a couple after-market super-long-range (non-DJI) batteries from Ali Express just as soon as I can find a buyer for my mother-in-law.

[vico]

There was indeed a minor bug for the cruising speed, which should now be fixed. The correct cruising speed should now transfer to DJI Fly.

Thanks for reporting this issue!

For POIs, as @wesbarris said they need to be linked to a waypoint, else DJI Fly drops them

[Mad_Pup]

This is great news Vico, and the speed with which this bug has been resolved is amazing. .

[Mad_Pup]

After several successful waypoint mission overwrites from the new Litchi Mission Hub on my laptop to DJI Fly in my iPad, I am now unable to overwrite a newly created Litchi Mission Hub waypoint mission into DJI Fly. Nothing has changed in the steps I used, which makes this error message all the more baffling.

The error message claims that I have NO waypoint files in DJI Fly, despite my having over a dozen of them, with several more that I created as overwrite templates.

There is clearly communication between the iPad and the laptop, so I cannot figure out why this overwrite process that worked just fine yesterday, suddenly stopped working today. Also I did remember to click on the Litchi Mission Hub Bridge icon before attempting the waypoint mission overwrite.

Exasperated, I decided to try to copy the waypoint file into my Samsung tablet instead, but that didn’t work at all, as has been the case all along. I went back to trying the overwrite process with the iPad after switching it off and back on, and switching the laptop off and back on as well, but the problem persists.

Any advice that can be offered as to how I can get this process working again at least for the iPad, would be appreciated. I was having some great adventures with my Air 3 before this issue cropped up, and I am at a loss as to why the file overwrite worked perfectly yesterday, yet would not work at all today, even though my procedure remained unchanged.

[TriBar]

What does it say in the upper right corner of your screen shot?
It looks like you somehow deleted all waypoint flights on your iPad,
Can you access existing waypoint flights directly on you iPad or the History list empty?

[Mad_Pup]

In the upper right there is a small banner confirming that the iPad is connected. All my waypoint flights are intact and not deleted in DJI Fly, so the message telling me they don’t exist is confusing.

Yes, I can also access the waypoint flights I copied from Litchi Mission Hub yesterday and the day before. They are all present and functional, yet the error message is telling me that they don’t exist.

[TriBar]

I would say there is a communication error between your iPad and computer.
this could be caused by:
-a faulty USB cable
-Accumulated lint/dust in the iPad USB port preventing the plug going in deep enough.
(the power-pins, which are used to detect if the device is connected, in the USB plug are longer than the data-pins)

[Mad_Pup]

I also suspect the cable. The market is flooded with counterfeit Apple Lightning cables, and the only genuine one I have was chewed on a while back by one of my hounds, but has worked fine despite it’s tattered appearance, until now. I think this is the issue, and now I have to try and find a genuine Apple cable that will replace the one I’d relied on until today.

[TriBar]

A picture is worth a thousand words.

[Mad_Pup]

I tossed it out when I saw the damage, but when the 3 different “genuine” Apple cables I bought locally to replace it all turned out to be counterfeit, I retrieved it and found it useable, until today, that is.

One of the downsides of living in a Third World backwater is that even if one is prepared to pay a premium for genuine products, the likelihood of being sold a cheap imitation is high.

[vico]

Do you see the flights in DJI Fly still (after restarting it)?

[Mad_Pup]

Yes, Vico, the waypoint flights I stored in DJI Fly over the past few days are all still there in the DJI Fly waypoint listing. To eliminate the possibility that those files might have been corrupted by an obscure bug, I sent the Air 3 out on a twilight waypoint mission over the forest that ended a few minutes ago.

The drone completed the flight and auto-landed barely two inches from its launch point at the center of an overturned 5-foot-diameter plastic tank that I painted like a giant rifle target to improve the positioning cameras’ precision. Everything went flawlessly, proving that the previously imported waypoint mission data is unchanged.

I am hoping this problem is caused by the cable finally losing a vital internal connection after 2 years of regular use in that chewed-up condition, yet the error message which incorrectly states that I have no saved flight plans in DJI Fly, and should create a dummy waypoint file, suggests that DJI Fly on the iPad is communicating with Litchi Mission Hub in my laptop, via the Hub Bridge. This hints at a possibility that the cable might not be the culprit.

I’m keeping my fingers crossed as I await delivery of several new “genuine” Apple Lightning cables, and hoping at least one of them will in fact be a real Apple product, and will resolve this odd problem that cropped up after several days of successfully copying assorted complex waypoint missions into DJI Fly from Litchi Mission Hub, and test flying each one in turn.