On my last flight today (quadcopter with APM2 running v2.9), at one point quite close to me I saw my quad do an uncommanded yaw, climb and start flying toward me. Looking at the tlog later I see it went into RTL but I was in Stabilize at the time and did not switch to RTL!

My Rx is set to go to ~920ms for failsafe but the logs show CH3/THR as normal so no failsafe?

I have 6 modes setup on my Tx via 2 switches, mode 6 is RTL (1877ms), mode 1 & 2 are Stabilize (1074ms & 1274ms), when I realised something was amiss I switched from STB2 to STB1 and it switched out of RTL and back into Stabilize as shown on the attached kmz file, then it flew normally and I landed with no problem.

So why on earth did it do an uncommanded switch to RTL?

Did it detect some kind of failsafe error? If so what?

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KevinB,

     During my testing I ran that section of code 200x more often than normal and was able to reproduce the issue in between 30seconds ~ 1 minute.  So I would have thought it would appear within about 1.5h of flight but I think in practice it occurred less than that.

Randy, does one of the 5 2.9 improvements include the fix to APM_RC.get_last_update()?

Tim,

     Yes, #5 is that fix.  Probably should have made it #1 'cuz it's the most important! 

@Drone Savant,

You like to talk about the DJI "banner". But you do not mention the back story for that case. DJI users, especially those with very expensive S800 camera copters where dropping like flies for months, no word from DJI. Total silence, as the users got more and more frustrated. Then suddenly DJI released an official patch, claiming having studied the fault and done extensive long term testing to make a new firmware. Those same months users kept crashing and DJI would not even confirm that there was a problem. That banner you talk about, was the first and only mention of the problem (serious electrical fault in the system) DJI ever did. Many months after the fact.

John shall we compare and contrast how the *original* PPM encoder flaws were handled by 3DRobotics / DIYDrones staff, developers, moderators and community in general? 

As far as I know there are STILL people experiencing fly aways from the old 9x PPM encoder interactions because no one made any official announcement. On top of that there was some discontent in the ranks of developers as to if it was even a necessary fix. There is STILL no public notification on that issue specifically. 

Sorry bro... you've got ZERO room to step up and complain about back story on a company that regardless of backstory DID make at least an ATTEMPT at notifying their user base. Regardless of how long it took them they DID notify. You guys have NEVER done that. 

I respect your work loads, alas I have no problem telling you there is not even remotely an apples to apples comparison there. Step up and properly document the historic (and current) PPM encoder issues (including when Hendrix warned you guys about BODLEVEL) and we will have some level playing ground to talk on. 

Bro, we'r gone down this road before. I'm not talking about PPM in this thread, period. Let's go PM or make a new thread if you want to talk about it some more.

But yes, you do have a point that required patches should be made more visible. Not arguing against that. Just saying that DJI is perhaps not the best example of how it should be done..

JAB forgive me as that is one of the best examples I had and is still currently a very valid issue for folks with legacy gear. It is basically partially unsolved even though you guys did go through great lengths to make some changes. The 2.9 fail safe changes are a testament to that in and of themselves, alas sans instructions and encouragement no legacy users will ever use that PPM code. Several ticking time bombs will sit on the shelf as such... I have a few myself (I'm too lazy to update the encoders). 

I am by no means a DJI bigot and have certainly seen some sketchy user notification / lack there of. That point on your end is well received and acknowledged (see the s800 ESC's failures in early models as an example - no banner for that!). Chris and many others here have mentioned stepping up to DJI level or even as using them as an example to strive toward. As such their banner for an existing issue was a good thing to reference. 

Right now as it stands... all inconsistencies included, as both a DJI end user / customer and as a 3drobotics user / customer I can say that ONE company has made *more* of an effort with MY particular business and keeping in formed on my purchases. One company has made efforts to replace *known* damaged / flawed hardware, one has not. 

DJI is by no means perfect... I just see a bit more *effort* out of them! 

I know you have rolled forward and kicked much ass on several other hot topics here... I respect that your leadership may ultimately help solve the required patches notification issues as well. 

For me it boils down to this "That banner you talk about, was the first and only mention of the problem" <---- at least they have a banner rather than a house keeping note on someone that tried to report the issue and got frustrated at the wall they hit. (Again not the best example but you get my point I am sure. Chris put more effort into calling ME out than he did publicly addressing that specific issue, which mind you is also a pretty darn serious one his userbase should be notified of to this day) 

i had a uncomanded rtl and was using 2.9 on a early 2.5 apm is there a encoder update? i have loaded 2.91 so the rtl hopefully will be fixed but i also never had a issue flying on my dx7 the first time this rtl happened i had swapped to a new 9xr radio and noticed your thread said 9x ppm problems ? The last phantom rtl bounced and flipped taking out 2 motors.i was going to swap back to a dx7 but if its just a ppm encoder update, bam problem solved!!! and thank you guys for all your hard work !!! im having a blast 

As a fellow DJI fanboi I totally disagree with that interpretation John.

1. A relatively small percentage of users experienced a problem. It wasn't everyone, it wasn't even the majority of users. 

2. How can DJI confirm there is a problem if you haven't found the problem?

3. A number of users got free replacement gear, S800s, frames, etc etc. As soon as the problem had been confirmed, the front page had a banner, the exchange program was up and running, and everything that could reasonably have been done was. 

It remains an example of how to deal with the inevitable problems that crop up in complex systems. Now, let's talk about Marco's famous flagpole crash, and how no announcement was made until the fix was out....

@Crasher,

Let's not make this a huge discussion. This is totally the wrong thread for it.

I think perhaps you misunderstood my reasoning. When DJI official released the patch (and admitted there was a problem as the same time), they gave out a video where they claimed to have done extensive long term testing with N copters flipping X times during a Y time frame etc. My point is that the moment the first of those test copters flipped, DJI should have grounded the S800's. At the very least confirmed the problem so that pilots could have made informed decisions with regard to safety. The S800 kit aren't cheap DIY quads flown for the fun of it. But a expensive tools costing easily more then $10K counting all the equipment including camera and lens, used by many professional to make a living.

So comparing a commercial WKM system bug to DIY opensource is apples and oranges.

Fear not, this will be my last post on the subject:

With respect, that's just hiding behind the DIY banner. Which has been done many times before. There are plenty of people flying expensive gear on APM, and many leaders of the DIYD community happy to compare the cost of APM to DJI when it suits their argument.

And this will be my last one also. :)

Sure, I agree that there have been many one sided comparisons between DIY and commercial solutions. It's one of the thing I would like to see more focus on. Making the advantages AND disadvantages of DIY/opensource more well known. So that people can make informed decisions as to what to expect from the system.

I am a big user of commercial systems. I have and fly all the big expensive ones, and there is a reason for this. The APM is great. Truly fantastic in fact, I would not dedicate time on it if not. But not my choice for $$$$ octos with professional cameras hanging from them. Not yet, at least.

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