Highly Unusual Error Message during Autonomous Litchi Flight

[Conservative Nihilist]

Of all the error messages that could appear on screen when one's quad copter drone is country miles away at 150 AGL while cruising along on a fully autonomous Litchi mission, the pop-up message I saw today would surely rank among the top three in terms of shock value. It read "Warning, M/C disconnected from Main Board. DJI solution : Restart the drone." The last thing one would wish to read as advice while the drone is in flight far from home, would be to "restart the drone" immediately.

I was confronted with that cryptic error message while the Mavic Pro Platinum traversed calm skies shortly after an early seasonal thunder storm, soaring 150 feet above a tropical swamp forest at twilight. Moments later a familiar Litchi message indicated that the drone had lost its connection with the RC controller.

Since virtually all Litchi waypoint missions on which I launch my Mavic Pro or Mavic Pro Platinum range well beyond the reach of the RC, Litchi's disconnect alert messages had never been a cause for alarm in the past. The drone always returned to base right on schedule thanks to Litchi's consistently reliable trajectory control, even if my RC controller had been turned off shortly after each autonomous waypoint mission departed, as is usually the case due to its being legal here.

The coincidence of an unprecedented and startling error message that suggested a catastrophic failure had occurred while the drone was in flight, at the very moment Litchi announced signal loss with the RC, unnerved me enough to hit the Return To Home button even though I was at that point convinced that the engines had failed whereupon my beloved drone plummeted into a murky swamp just as it was getting dark.

The reassuring blue "Return to Home" banner on the Litchi screen did not appear as it usually would after RTH was actuated on many occasions in the past, and that further reinforced the notion that my Mavic Pro Platinum was missing in action. All the same I remained outdoors as my hopes faded of ever seeing the drone until suddenly the screen came alive again and the drone was inbound at 25 mph, with more than enough battery power to complete the return to base.

After this bizarre incident whose cause is still a mystery, I am going to carry out a full calibration of the compass, IMU, sensors, and camera even though it hasn't been a month since I performed all those preventative measures. If any Mavic Pro pilots out there have every encountered an error message mid-flight that refers to a disconnect between the "M/C" and the "Main Board", I would be grateful for any insights that could be offered as to what exactly might have triggered such a strange error message.

My only hunch thus far is that because the drone had just returned from a 7-mile round trip Litchi mission on a cool evening before I launched it again on a second mission that nearly went awry, overheating might have been the culprit. Still and all I would be curious to hear any thoughts on what may have triggered such an unexpected error message that initially appeared to confirm an abrupt departure from controlled flight by a Mavic Pro Platinum that has served me well till now.

 

[gmonatl2]

I have lost two drones on Litchi missions not that unlike yours. One message matched yours exactly and i still have not recovered the aircraft. The second I believe a propeller came off and i recovered the drone with several hundred dollars of damage. What do your flight logs say? I am curious. I know I haven't really answered your question or solved the problem, but am interested in knowing what you find.

 

[Conservative Nihilist]

I have lost two drones on Litchi missions not that unlike yours. One message matched yours exactly and i still have not recovered the aircraft. The second I believe a propeller came off and i recovered the drone with several hundred dollars of damage. What do your flight logs say? I am curious. I know I haven't really answered your question or solved the problem, but am interested in knowing what you find.

Haven't checked the flight logs yet but after reading your account I realize how lucky I was to have the drone return home after issuing that stress-inducing error message. I'll see if I can't figure out how to retrieve the flight logs to post here in the hopes someone can shed some light on what happened there.

One thing I forgot to mention as well was that the camera went out of control on the return leg of that flight, and the horizon tilted wildly until it finally returned to normalcy as it closed in on its landing site. That incident was very worrying indeed, considering that my small drone fleet has covered over 3,000 miles under Litchi control without one single mishap to report until yesterday.

 

[Conservative Nihilist]

Another thing that just came to mind was that when flying long-range Litchi missions that extend miles away from home, perhaps it is best to switch off the RC controller after the drone departs to prevent intermittent signal connectivity with the RC from triggering flight anomalies.

Because it is perfectly legal to do so here outside the USA and EU, my normal practice had always been to switch off the RC after the drone departed on long-range Litchi missions, but after I recently ran a full calibration of the IMU, compass, camera, and sensors, I found that the RC signal range increased dramatically, which I never expected.

Because of that increased RC range, I had begun to leave the RC on for the entirety of each flight but then started to doubt the wisdom of doing so when the camera did a wild dance a couple of times, suggesting that intermittent RC connectivity was still an issue. So with that in mind, I may revert back to my previous practice of "flying blind" during Litchi missions.

 

[Meta4]

the pop-up message I saw today would surely rank among the top three in terms of shock value. It read "Warning, M/C disconnected from Main Board. DJI solution : Restart the drone."

It was just a glitch that triggered the message .. a false alarm.
These are seen occasionally.
I've seen a couple saying that a prop was loose or had come off, when it was obvious that the drone was flying completely normally.

Moments later a familiar Litchi message indicated that the drone had lost its connection with the RC controller.


The coincidence of an unprecedented and startling error message that suggested a catastrophic failure had occurred while the drone was in flight, at the very moment Litchi announced signal loss with the RC, unnerved me enough to hit the Return To Home button

Once you've lost signal, pressing the RTH button won't achieve anything.

I am going to carry out a full calibration of the compass, IMU, sensors, and camera

Those are completely unnecessary.
None would address the issue that the false alarm message referred to.

even though it hasn't been a month since I performed all those preventative measures.

None of those are preventative measures anyway.
You don't need to tinker with the drone that much.

My only hunch thus far is that because the drone had just returned from a 7-mile round trip Litchi mission on a cool evening before I launched it again on a second mission that nearly went awry, overheating might have been the culprit.

Unlikely.
DJI drones can fly multiple back-to-back missions without over heating.

 

[Conservative Nihilist]

Meta4 if it were possible to vote two likes for your highly informative post here, I'd have done so for sure because you cleared up several mysteries at once. With over 3,000 miles of cully autonomous Litchi flights uncovered thus far, I really thought I'd seen every possible quirk that one could encounter, but this response you've kindly offered here proved me wrong yet again.

Over all those hours of drone flight racked up over the past 5 years, I had never once encountered a completely random error message of the sort that sent me into a minor panic the other day. Matter of fact, the only two warnings I'd ever encountered during Litchi flights were the disconnection warning and the RTH alert. For peace of mind, I'll probably revert back to my long-standing practice of simply turning the RC controller off as soon as the drone has departed on autonomous missions.

This is one instance where the old adage of "What I can't see can't hurt me", may in fact hold true haha. Finally, it is reassuring to hear from a far more knowledgeable drone operator that my concern about overheating drone motors was unfounded. I thank you kind sir for taking a moment to further broaden my understanding of these amazing machines that enable me to experience the dream of flight from the safety of my armchair.

 

[MS Coast]

Because it is perfectly legal to do so here outside the USA and EU, my normal practice had always been to switch off the RC after the drone departed on long-range Litchi missions,

I'm curious. Where is that legal?

 

[Conservative Nihilist]

While the forum mods no doubt see my current location with an unsettling precision of ten feet or less, I must be coy in all public online forums when it comes to geographical disclosure simply because rules and regulations sometimes change abruptly overnight and without prior notice, on a whim, as it were.

Suffice it to say, the regions of our planet where drone flying restrictions are non-existent or ambiguous greatly outnumber the jurisdictions where FAA and CAA guidelines hold sway. God bless Antarctica.

 

[MS Coast]

While the forum mods no doubt see my current location with an unsettling precision of ten feet or less,

Sounds like you provide them with a streaming broadcast with lat/lon data from the GPS in your shirt pocket.

 

[Conservative Nihilist]

Sounds like you provide them with a streaming broadcast with lat/lon data from the GPS in your shirt pocket.

Haha my presumption has always been that forum mods can see the IP addresses AND GPS coordinates of all forum visitors. If only I'd known that level of geo-locational precision requires special gear and is not readily derivable from one's IP address, I wouldn't have gone to so much trouble to be polite in online forums haha.