Question about RTH while flying with Dronelink

charles folds
I have a DJI Mavic Air 2.
There's a fairly big property that I need to do some mapping on, and I've already got it planned in Dronelink. I've gone to the site and flown a few times (using the DJI app) and at the farthest edge of the property the signal gets weak (it's in the mountains). I even had one time I lost signal, but of course as usual the drone automatically starts to RTH and I pick up the signal again pretty quickly.
What I'm wondering is, what happens if I were flying the flight plan using Dronelink and drone hits that spot where the signal starts to get sketchy....does the drone still automatically start to RTH? I'm not sure, because it wouldn't be using the DJI app at that moment. Does it keep flying its flight plan regardless of signal?
Anyway, before I tried this I wanted to make sure how this works- I suppose I've never really known...does the drone know internally to RTH when signal is lost? And if that's the case, what about when using Dronelink?
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Comments

55 comments

  • Comment author
    Bob Scheffler

    I saw nothing in the records of a 10% battery condition. All I saw was 92% battery

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert

    I read that post but that was obviously a strange error. The software must have been indicating a critical low battery at 10% or less when it wasn’t. Not sure why it did that other then the device issues we’ve discussed. I Really think a better device will solve most of your issues. I’m curious to hear if trying that iPhone you got will solve most of them. You should know after the first mission. 

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  • Comment author
    Bob Scheffler

    I reviewed the flight record for the day drone decided to make emergency landing and it never recorded 10% battery it recorded, 90%.  I also looked at the flight records for testing distance, for some reason it only recorded 2 flights and I know I made 4, but you were right, I was losing contact for short periods and then the flight would resume. For example: the shortest flight of 1,291 feet fist lost contact at 901 feet for 3 seconds but continued.  I have not been able to try the iphone yet because it rained all day and 40 mph winds.  Hopefully tomorrow.

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  • Comment author
    Bob Scheffler

    Mike, I tried to connect my RC to my wife's iphone but for some reason I did not have a cord that would work.  So since I had disconnected my tablet, which is all zip tied to the RC, I tried flying with my Samsung S21 phone.  The image transmission signal weak msg. was gone.  I then tried to use Dronelink and got a msg. that it was not compatible with the software.  Strange because it always was. 

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert

    Yep. It needs a lightning connector. If you bought the drone new it should have a cord for IOS device. Usually comes with three different cords. They ate only about $10. 

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  • Comment author
    Bob Scheffler

    I think I just lost the cord. Or the connection is tight and I don't want to force it. We use charging bases and her phone is pretty new so the socket could be real tight. As far as the transmission signal msg. It doesn't come up on tablet or phone. I don't know what happened

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  • Comment author
    Bob Scheffler

    I did another RTH test today.  I just created a straight flight beyond where I usually lose contact with a RTH when mission completed and stood by my truck in case something went wrong.  I have the flight record but I can't remember how to send it to you to look at. The mission launched without problem, went to 200 ft., report from airdata said 14 mph winds at 200 feet.  It flew for approximately 2 1/2 minutes and reached 1085 feet with 80% battery.  Right about this time the speed was decreasing to the point of 0 mph, and it fluctuated for a few seconds then I received the msg. that the RC was receiving a weak signal. The last msg. was destination cannot be reached.  I waited, what I thought was a minute, but the flight record said 30 seconds. It either flew or the wind blew it to 1,099 feet where the flight record said, "79% Battery at maximum distance".  At approximately 3 minutes and 2 seconds into the flight I hit the RTH button and it flew back.

    Never in the flight record did it say it lost contact yet the drone did not move for at least 30 seconds more like 45 seconds according to records and it never mention anything about a weak signal.  I did not have anyone available to report from the other end so again I was getting nervous that I might hit RTH and nothing happened.  But the fact that RTH did work means that it was getting a signal but why then did the drone stop flying? 

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert
    • Edited

    Maybe Jim can answer this better. I believe if the Aircraft signal is too weak the mission may not continue and pause because it knows it can’t complete the mission based on the connections weak signal. I’m not sure on this but I thought I read something about this before. If the signal can be increased by adjusting antennas or moving your position/ location to increase the signal it may be able to continue mission. If the signal is improved you should be able to click on the play button and resume.

    As you stated, since it is still connected even with a low signal it will RTH when manually activated so the flight records won’t indicate a disconnection. I don’t know if the records will indicate a weak signal or not.

    The distance you noticed change from 1085 to 1099 is only 14 feet. It may have been the wind and these drones only have an approximate accuracy of about + or - 4M (13 feet) so need any small deviation may be a combination of both.

    Did the DL app indicate it was paused ? If so you can click on the button and try resuming if signal is increased.

    Were the transmission signal bars in the DL app low ?
    IE: One or two bars ?

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  • Comment author
    Bob Scheffler

    I did not notice the bars, and the record did indicate a weak signal with the RC. I still don't know how long I should have to wait before a drone goes from just hovering to RTH. Also is the problem with my drone or software?

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert

    It will hover until the battery depletes and the first low battery triggers RTH. The Mini should hit first low battery RTH at about 20%. The reason it just hovers is I believe due to the weak signal and it gives you a chance to adjust antennas, position etc…, as I stated above. If the signal can be increased to continue the mission you can then hit the play/ resume button and see if it continues.

    Do you remember if the button symbol was indicating paused, or the arrow/ play was showing. Any mission can be paused by the app if an issue or manually by the pilot during the mission. The mission can be resumed It and it should continue and complete the mission as long as there are no issues like weak signal. If I remember correctly the DL software is sending commands to the control sticks as if you were flying it in Milliseconds. This is one reason you need a powerful device to process and handle all of the input which is being sent extremely fast and also a strong connection. I’d ask Jim directly about the weak signal and if it is possibly causing the pause.

    I don’t believe it’s your drone. I believe the software is working correctly. It just needs a strong enough signal during the entire mission.

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  • Comment author
    Bob Scheffler

    This long post started because Charles fold asked if his drone looses signal will it return home. I answered him saying I believe it will wait for a specific time and execute RTH. You agreed. Now I am understanding that you think it will wait until 10% battery is left. I am going to try to find the answer in the manual.

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert
    • Edited

    He asked several questions and are different situations. The two you are asking about I’ll try to be more specific.

    1. It will RTH, hover or land when it fully disconnects Depending on your settings in the Fly app. A Full disconnect only after approx 11 seconds which is what DJI set the timeframe at.

    2. If it doesn't fully disconnect and just indicating a “weak signal” or Sketchy signal as he stated then the pilot still has a connection between drone and controller. It will not Auto RTH and the mission may pause as you are having. Pilot has the ability to adjust their position and/ or antennas and try for better signal then try resuming, fly back manually or RTH. 

    3. The first low battery auto RTH is at about 20% which is what DJI has it set trough their firmware. Unfortunately this is not adjustable in the DJI Fly app. With a weak signal it will hover until it reaches the low battery percentage and then RTH.

    I know this thread has gotten really lengthy. The bottom line is the drone needs a strong signal to work throughout the mission. DL is working correctly if it is pausing, failing or goes into RTH during mission due to a weak or no signal.

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  • Comment author
    Bob Scheffler

    According to the flight record the drone lost signal twice over 11 seconds one period for 13.6 seconds and the other for 24.8 seconds.  I just reviewed the manual and you are correct.  It should RTH after 11 seconds of disconnect and it did not.  I called DJI and they agreed that something is wrong and opened a case for the drone to be replaced.

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  • Comment author
    Joel Stolarski

    Post for Following. Have a mini. Just installed app. Will add what I learn.

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert

    Hi Bob. Understand. Also I didn’t mention when it was hovering and why you could not take back control of the drone manually and had to hit RTH. Since the mission paused and waiting for you to to try and resume the mission if possible, you can’t take back control manually. The DL app is still connected however weak other signal is and won’t let you use the sticks. If it happens again you need to close the mission then go back into the plan you are running and click on the three dots on the right side and “Abort” the mission. Once you do this you should be able to manually fly the drone with the DL app since it does still have a signal even if it’s weak. This is obvious since you can hit RTH and it worked. Maybe you already knew this but if not this will allow you to manually fly it and bring it back, ascend, etc..

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  • Comment author
    Bob Scheffler

    The RTH button would NOT work until I got into my truck and drove closer to the drone.  Anyway I explained all this to a DJI tech, as well as the time the drone performed an emergency landing with 92% battery and they agreed something is wrong.  They still had records of the emergency landing issue because I contacted them about that.  I just finished the process to replace drone and they will send me a new one as soon as I send this one back. They e-mail me a postage paid label to send my drone back. They tried hard to make me agree to a repair but I read back their own contract which is labeled replacement contract and they finally gave in.  I recall that they did this to me before.  I was getting a constant warning that the gimbal was overheating, to return immediately.  They tried to fight me then also.  So it will cost me $36 to get a new drone.  But that is my last replacement, so this one had better last a little longer.

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert
    • Edited

    Ok. Hopefully it will fix many of the issues you were having. I’ll keep an eye out for an update. 😀👍🏼.

    You could have purchased an additional one year Cafe Refresh + from them as long as there was at least one replacement. Now that both have been used they may not though. Just a thought and since you have had issues maybe can they can still allow another refresh. More money but a thought. Can’t hurt to give it a try of interested. 

    https://store.dji.com/product/dji-care-refresh-plus-mavic-mini

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  • Comment author
    Bob Scheffler

    I already purchased my second care and refresh insurance, that is what I am using, my last one.  I am going to try one more test today if the weather holds up.  I am going to try and do it right with a second person.  Hopefully I will get a second flight record to show the issue.

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  • Comment author
    Bob Scheffler

    I performed another test today using my son to wait where I usually lose contact.  The first test the drone flew the distance and completed the mission with only one telemetry delayed msg. approx 2,000 feet.  The second one lost complete contact, the drone just hovered.  I waited a solid minute then hit the RTH, got the beeping but the drone did not budge.  I shut down Dronelink and opened DJI hit RTH again, still nothing, drone is still just hovering.  Started to walk to my truck to drive over and it just started to return home.  I must have had no control for a solid 2 minutes probably more.  I reviewed the flight log and it said I only lost connection for 5 seconds.  Well I hope the new drone does not do this.

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert
    • Edited

    Definitely problems with it. Hopefully the new drone will correct most of your issues and works correctly. I’m curious if you have tried the same mission with the other Mini ?

    Possible that the extremely low signal or even no signal bars is still going in and out trying to re-connect and it needs to be “fully disconnected” for that amount of time before auto RTH. It may be better in the future if any issues waiting for RTH to trigger to just turn off the controller. That will insure there is abosuley no transmission signal at all which should then trigger it. Anyway, waiting to hear good news with new drone.

    As far as the flight logs, I don’t trust them for a accuracy all the time. I’ve flown short 5 minute or so flights with DJI Fly and it reports only about 1 to 2 minutes of flight. My Airdata app shows the roughly 5 minutes as it was. I don’t like how the DJI flight records are set up and what it reports but overall it’s nice to have the data. 

    Enjoy Bob. 

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  • Comment author
    Bob Scheffler

    I received the shipping label to return my drone but now I am beginning if there is a problem with DJI drone.  I flew 2 flights but not with Dronelink.  I hand flew with DJI Fly.  I flew beyond range, in this case it was actually by accident because I was only at 900 ft. distance.  I was performing the flights because I just got a new update and thought they may have solved the "Weak Transmission Signal" msg., but no they did not.  Although I don't see it when flying with DJI only when flying with DL.  At any rate I rcvd. the msg. at 900 feet of a weak signal, the video froze and within 20 seconds the RTH was automatically activated.  I flew the same rout and again same thing happened.  I flew a DL mission and the "Weak" signal was on. the mission did not complete because the micro chip filled up.  I took the tablet to my computer to review the flight records.  DJI had no flight records, it did not even have a folder labeled flight records.  I looked at the DL flight record and it was there but there was no indication in the records that the flight was stopped.  So now I am starting to wonder if RTH problem is with the DL software and not the DJI.  I till had that strange emergency landing in the summer so I believe I will probably still return the drone since I already paid my $40 to replace it.

    By the way you mentioned using the same mission with the other mini.  Are you referring to the one I had before?  If you are DJI has that, you have to send it back to them to get a new one.  My son has a mini but I don't believe I can fly his mini with my remote, or can I?  And he was too afraid to use the Dronelink software. 

    I think I will keep the drone for a little more testing, maybe take it to the beach, which will be empty here, that way I can have a long flight at a low altitude and can't loose it in a tree. 

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  • Comment author
    Joel Stolarski

    I was able to fly my Mini with dronelink. The flight plan worked perfectly. Only at the beginning it was warning magnetic field intererference. I disregarded that and the drone did a simple flight plan in a wide open field. Did not have transmission loss with DL. When I decided to do a second flight with DJI Fly I had to do the gyro and imu which I messed up on, in hindsight. At any rate, the Mini was only about 1,486 when when weak signal showed up, and then a following low battery warning which went into RTH. Going to try today with everything charged properly. I'm new to drones, but not rc. So, will report back to see what is going on. Will make sure everything is charged and try and do gyro and imu calibration procedures as best I can. There's no table or anything out there. It's a wide open field.

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  • Comment author
    Mike (Arizona Wyldwest) Dronelink Expert Dronelink Expert
    • Edited

    Hi Bob. Wow this thread has gotten really long. Lol. Anyway, yes you can use the same controller with your sons Mini. Any DJI drone which uses the same controller can be used on another matching drone. Just need to go into the DJI app and select “Control tab” and “Connect to aircraft.” Very easy, quick and simple.

    As far as flight records, when using DL none of your flights are recorded in the DJI app since it wasn’t being used to fly the drone. This is why I use Airdata integration for all my flight records. All my DJI Fly and DL flights are kept this way. You can setup DL to automatically send the flight logs to Airdata which is really nice and has a ton of information. Battery temp, cell volts/ amps, controls, media, sensors, etc. You can use for free unless you need to save a bunch of flights. I believe the free version keeps 200 flights which is not a lot but you can delete older flights if not wanting to keep more. I’ve got the 1200 flight plan and it’s been about one year with 390 flights. Can’t hurt to use the free limited version.

    As Jim has stated before, That part of the UI is from the DJI UX SDK, so the weak transmission signal is not on their end. Android devices seem to have had this as you know for quite awhile. I’ve seen no issues using IOS devices so it does seem like it’s just with Android. 

     



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  • Comment author
    Bob Scheffler

    I have been grounded for almost 3 weeks.  I sent my Mini back to DJI for the 2 issues I had which I could not find reasons for them happening.  First was the emergency landing with a full battery and the second was the RTH problem of losing connection for extended periods without RTH being automatically issued.  DJI looked at the flight records and agreed there was some unknown issue, probably software they stated.  I was returning the drone under their insurance policy, for a replacement.  One person said they would analyze the drone and if it was not pilot error they would give me back my $40.  Either way I would be getting a new drone.  I said I was not concerned about the $40 I was just interested in what was causing the problems.  I then received another e-mail from someone else at DJI saying I would be charged for analyzing the drone because it was out of warranty.  I thought buying DJI Care refresh+ was like buying an extended warranty?  I guess not depending on who you talk to. At any rate I just received an e-mail saying my new drone was being shipped out today.  But that's the end of my drone replacements.  Probably will not get much more flying time around here, it's getting pretty cold and the drone does not do well in cold weather.

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  • Comment author
    Joel Stolarski

    Best get Airdata UAV . If you sync it correctly with DJI Fly app, you will get so much data on all parameters of the drone, will make your head spin.

     

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