Mini 3 standard shortcomings

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Today, and for the very first time, I tried the Litchi Pilot app with a waypoint mission I created using the new Litchi Mission Hub, for my rarely-used Mini 3 quadcopter.

Because I hadn’t flown the Mini 3 for a while, I checked to see if the IMU and compass might need calibration, but there was no indication that they did, so I launched the drone. After a few uneventful minutes, I noticed that the camera view, and the map view both showed that the drone had begun to yaw in random fashion both to the left and to the right, deviating about 10 degrees from the flight path as it traveled at 28 mph along the gradual arcing trajectories I drew up for it..

An early tropical rainstorm rumbled a few miles off, but the skies were calm closer to home where the drone was carving gentle wide-radius turns during this test flight, and there was no on-screen warning of high winds as I continued to note the series of abrupt un-commanded yaw motions by the drone as it progressed along the flight path.

Soon I noted something I had never seen before, over thousands of past Litchi waypoint missions flown with various older DJI drones. The Mini 3 began to veer off the flight path by as much as ten feet, before correcting itself and reestablishing itself on the true course, often while yawing noticeably.

I finally hit the RTH button when at a point the Mini 3 embarked on a series of complete 360-degree yawing turns, as though the drone was disoriented. Oddly enough, as the Mini 3 made a beeline back home along the RTH vector line, the yawing motion subsided completely and the drone’s orientation remained in perfect unwavering alignment with the RTH flight path line.

With the storm edging closer, I wrapped up my Litchi Pilot flight tests for today, but I’ll be sure and calibrate both the IMU and compass of this Mini 3 before I launch it on the same test flight waypoint missions tomorrow, to find out if the yawing glitch recurs. .

I decided that those un-commanded yaws were worth mentioning in this beta feedback forum, in case it is a known issue either in general or for the Mini 3 alone.

The Mini 3 has always been the ugly duckling of my DJI drone fleet, due to the fact that it cannot continue waypoint missions after RC signal connectivity is interrupted, and that is why it took me so long to test it with the Litchi Pilot app. Now that I have seen this little wonder can handle complex waypoint missions, however, my interest in the lowly Mini3 has been revived, after owning it for over a year during which I rarely dusted it off for use.

I’d be grateful for any thoughts that can be shared about the causes and possible remedies for the odd yawing motions I observed when I flew this Mini 3 using Litchi Pilot for the first time.

All told, the Litchi Pilot app is a brilliant work of software engineering that I know will become as reliable and precise as the original Litchi app that has brought my drones safely home over hundreds of flights that reached out far beyond the horizon. If it turns out that the yaw motions I described here relate to a previously undetected bug, I’d be pleased if it turns out that I played a small role in narrowing down on that bug so that it could be terminated with extreme prejudice by the Litchi code-meisters.

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Mini 3, uses Ocusync 3 (not nearly as good as O4) and can only use the Litchi engine for waypoint meaning there will be added delay as Litchi controls the drone during the flight. If there is high wind, or if the signal is not very good, you will get issues like you described. This is not a setup suited for long distance flights.

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Ah, I see. The way the Mini 3 oscillates left and right of the path gives the impression that it is searching for the next waypoint along the flight path. I just flew the drone again with the speed reduced from 30 mph to 28 mph, to test my speculation that the speed was excessive on those earlier test flights, but the random yawing continued intermittently despite the slower speed.

It is odd that my older DJI drones, including the Phantom 3S, the Mavic 1 Pro and Mavic 2 Pro, all fly Litchi waypoint missions smoothly and with none of these oscillations, despite their transmission technology being of an earlier vintage than the Ocusync 3 used by the Mini 3.

Perhaps it is mostly due to that puny size and low inertia of the Mini 3 that it is prone to oscillations when the wind picks up along the way.

While I really like the Mini 3’s flexibility that allows the operator to change the image magnification from 1 to 2 to 4 power on the fly, which is a feature that my Air 3 doesn’t offer, the instability of the Mini 3 on windy days is yet another reason that I will stick with my decision to sell it and buy another Air 3 later.

This clarification is appreciated, Vico. I can now rest assured that Litchi Pilot is not to blame in this instance.

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Well that’s not to say we can’t make improvements, but in any case the additional delay of controlling the drone from the RC, rather than onboard makes this task more difficult. Older drone models like Phantom 3, Mavic Pro etc actually fly using their onboard engine, that’s why they can go out of signal range.

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Thanks to this explanation, I now better understand the shortcomings of that infernal “Virtual Sticks” disability that hobbles drones designed without the key capability to store all waypoint data before takeoff.

With this in mind, my all-time favorite DJI drones are the Air 3 and the venerable Mavic 2 Pro. Even when the Mavic 4 Pro drops to within my affordable price range, I’ll remain content with these older workhorses, especially since these old eyes aren’t too finicky about the resolution of drone video footage.

All things considered, my ideal DJI drone lineup would comprise three Air 3s and three Mavic 2 Pros.

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After another test flight at dusk today in perfectly calm skies, I paid attention to the signal strength bar display while monitoring the Mini 3’s progress along the flight path of a waypoint mission in Litchi Pilot. From this test, I am now certain that the wandering yaw motions of the drone ONLY occur when signal strength drops below 4 out of the 5 bars indicating signal strength.

When the Mini 3 flew close enough to the launch point for 4 or 5 signal strength bars to be illuminated, the yaw motions tapered off, and the drone remained locked on the flight path in smooth, stable flight, following the curvature of its defined course without the slightest deviation. Once the signal strength dropped to 3 out of 5 bars, the yaw motions resumed with a vengeance.

So, just as you surmised earlier, Vico, the Mini 3’s accuracy in following the flight path degrades as its distance to the launch point increases, due to signal delay that only becomes noticeable when signal strength drops below 4 out of 5 bars in the indicator at the top right corner of the Litchi Pilot screen.

With this confirmation that the signal transmission delay which plagues Virtual Sticks-reliant drones like the Mini 3, not having that key capability of loading all GPS data into onboard memory before takeoff on waypoint missions, my mind is made up to sell the Mini 3 and then buy another Air 3 to replace it.

My initial purchase of the Mini 3 was hasty and impulsive because I was convinced that an SDK would be released for the Mini 3, only for DJI to withhold that SDK forever, it appears. Oh well, at least I got to see for myself how essential it is for any drone I use to have the ability to store all waypoints on board so it can complete missions autonomously, even when RC connectivity is interrupted or lost.

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For your situation a drone with DJI Onboard waypoints capability will work better. Just realize if you still want to use the Litchi mobile app to actually fly the missions then you would need a drone like the Mini 4 which has DJI SDK support. This way you could use the Litchi mobile app to fly either a Virtual Stick or Onboard mission. I have the Air 3 which doesn’t have the SDK for third party apps so it needs to be converted to a DJI Onboard Waypoints mission and flown with the DJI Fly app. Also even though you can convert and fly missions with the DJI Fly app, using DJI Waypoints conversions have limitations and will not ever be a one to one conversion. I’ve flown quite a few of my Dronelink plans converted to a DJI Fly KMZ and they have worked fantastic but something to consider. It will depend on your needs. Enjoy.

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My purchase of the Mini 3 was an impulse buy I made because I value long flight times above all other drone specifications. Reading about the Mini 3 offering “Plus Batteries” capable of powering flight times over 40 minutes, and also egged on by unsubstantiated rumors that DJI would release an SDK for the Mini 3 so that it could store all waypoint data before takeoff, led me to hit the buy button, when I would have been far better off waiting and buying a Mini 4 Pro for not much more.

Even though the Air 3 also never got an SDK that would have enabled it to be flown with Litchi rather than with DJI Fly, I agree that its saving grace is having that key ability to store all GPS data for waypoint missions imported into DJI Fly from the new Litchi Hub.

I bought Dronelink back in 2021, but found its user interface cumbersome compared to Litchi, which I purchased around the same time for both Android and iOS. I thus never launched a single Dronelink waypoint mission, while my older Phantoms and Mavics covered a conservative estimate of 3000 miles flying hundreds of Litchi waypoint missions that I created over the years.

With your mention of Dronelink as doing a reasonable job of creating waypoint missions for DJI Fly, I might dabble with that platform again, though I doubt it will replace Litchi as my all-time favorite drone flying app. I’ve put my Mini 3 up for sale and will later replace it with either another Mavic 2 Pro, or a second Air 3, which are likely to remain my favorite DJI models for quite a few years to come.

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Every pilot has their opinion. I actually l find Litchi to be very cumbersome. The biggest issue pilots have with Dronelink is when first starting out there is a step learning curve. It is such a powerful app it takes a good amount of time to learn all the functions, features and settings. You pay more but get a ton more. I have tried many times to create the same plan with both apps and I can create a Waypoints, Orbit or Mapping plan with both apps and it’s far easier and quicker with Dronelink then Litchi. Also having the ability to use multiple components all in one plan is a big plus. Anyway, It all comes down to pilots choice. Enjoy.

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The existence of an SDK and whether or not a drone provides on-board waypoints is independent of each other. An SDK was released for the Mini 3 Pro over a year ago. That is what allows it to be controlled with the Litchi Pilot app. However, the Mini 3 Pro does not have on-board waypoints. Similarly, the Air 2S is supported with an SDK, and therefore, Litchi, but it also does not have on-board waypoints.

Conversely, there is no SDK supporting the Mavic 3, Air 3, Mavic 4, or Mini 5 Pro. However, each of those drones has on-board waypoints.

I just wanted to clear that up.

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I am constantly getting SDK availability mixed up with the ability of drones to store all waypoint data onboard before takeoff, and I think my dyslexia may have something to do with it, along with the fact that I frequently switch from flying a Mavic 2 Pro, to a Mini 3, and an Air 3, all of whose capabilities and limitations differ in ways I lose track of now and then.

I now recall this distinction has been made in this forum before. This reminder is appreciated. I’d have considered a Mini 4 Pro as a replacement for my Mini 3, but I prefer a heavier drone with more inertia for those windy days. The Air 3 and Mavic 2 Pro have a nice heft to them.

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Yep I’m the same @Mike_M , I can probably put a mapping mission together in Dronelink quicker than I can work out how to start a new mission, in Litchi

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You have already gotten some excellent replies here, especially regarding the Virtual Stick Mode (the way that Litchi has to interact with the aircraft when waypoints cannot be onboarded).

To add, it seems to me the weird yawing motion you saw could be the toilet bowling typically seen when a drone doesn’t have a good magnetometer bearing. The “straight as an arrow” type flying you saw on the rth path might indicate it was able to correct itself, once the onboard flight mode (rth) was allowed to take over. Just a guess of course.

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Thanks for the feedback.

As with any tool you’re not yet familiar with, there is a learning curve, although we try our best to make Litchi Hub as easy and intuitive as possible.

Here is a quick example showing how to create a mapping flight in Litchi Hub:

We’re always looking for ways to make it easier and faster to use, so please do let us know which parts feel less intuitive or slower compared to other planners you may use. Specific examples are especially helpful.

PS: We know some users have found it difficult to create a new flight, and we’ve recently made improvements in that area. More refinements are also coming as we continue developing Litchi Hub ahead of its public launch.

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I would like to untangle this thread because it has morphed from Mini 3 shortcomings into a comparison of Litchi vs Dronelink. However, it is no longer obvious where to split it.

For what it’s worth, I have used both Dronelink and Litchi (and other flight planners). I found Dronelink to be quite non-intuitive and cumbersome to plan a simple mission. For the most part I find Litchi works they way I would expect it to. It just makes sense to me. I’ll admit that it has been a while since I’ve used Dronelink and I’ve spent a lot of time with Litchi. So, anything is easy if you already know how to use it. There are a few things that I would change or add to Litchi’s Mission Hub but in my opinion flight planning is so much easier with Litchi than any other flight planner I have used.

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Everyone has there favorite apps. It was no big deal so maybe we should just move on. Enjoy.

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Hi Vico. Thanks for the info but it’s not new to me. I began trying both the Litchi Hub and the DL Web app in August 2020 knowing the SDK was going to be released for the MA2. I spent about 2 hours or more most days of the week for about a month so I could learn both apps. So it’s not that I don’t understand the app it’s the actual setting up of a plan and any functions I want to utilize. So I am familiar with Litchi and the majority of the features/ functions. Back then Litchi only had Waypoints (path component). With DL having Advanced Orbits, Advanced Mapping as well as Waypoints, (path component) it was a big selling point as well as being able to use multiple components all in one mission. Your addition of mapping and the new and much better Litchi Hub UI it’s a big improvement so that’s a great change. Unfortunately you don’t support Orbits for Legacy drones like my MA2 and the MM. I don’t want to continue to use this thread since it’s off topic as Wes stated which is actually about the Mini 3. I’ll start a new thread soon with some info on one topic which is regarding POI’s to see of you can change the way they work. Others have already posted questions regarding POI’s but I believe you can improve on them. Thanks again.

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