Solex causing Solo to twitch

droneswag420blazeit · Mar 8, 2017

I was flying with Solex 1.3.3 yesterday, and the app seemed to cause the solo to twitch in the air in a constant rhythm. Below is a video of the effect (sorry for the short length).

Just for the record: A few days ago this solo was factory reset, the pixhawk was reset, and I am using a new NVidia Shield K1 with newly downloaded Solex 1.3.3. So I am essentially working fresh here. Additionally, I spent 4 batteries testing different things like switching to the Solo app, changing props, restarting tablet, GPS on/off, messing with settings, etc. I could not find any constant variable that went with this behavior except for Solex. It happened when Solex was connected, and it was rock solid when Solex was not connected.

Any ideas?

andrew.baker.142 · Mar 8, 2017

Don't have any ideas for you. Didn't do the twitching when Solex was disconnected?

Sent from my iPhone using Tapatalk

droneswag420blazeit · Mar 8, 2017

Thanks for the reply. Yes the twitching does not happen when not connected to Solex. I just uploaded another short video taken flying with the solo app:

Kelly Schrock · Mar 8, 2017

To clarify: There is nothing in either Solex or the Solo app from 3DR that would (or even can) cause the Solo to twitch or fly erratically. There's a telemetry connection, video stream, and a channel for sending commands like "change vehicle mode", but that's it really. Nothing in the app has that level of control over the flight controller.

For what it's worth, I've experienced a few bouts of this strange behavior lately myself. In 19+ months of flying, I've lost GPS in clear space once. But in the last month, I've lost GPS 4 times when flying in my back yard (where I've flown ever since I've had the Solo), and I get occasional twitching behavior where the motors want to increase speed and decrease speed in a steady rhythm. I land, power down, power back up, launch again, and it's fine, using Solex both times.

pyrate · Mar 8, 2017

Yep two totally different functions of software
have you messed with settings or firmware on the flight controller?
that is what would mess with PH

droneswag420blazeit · Mar 8, 2017

No I haven't been doing anything weird like that. As I just posted on facebook, I will probably do more testing and report back either way.

Kelly Schrock · Mar 8, 2017

I'm going to take mine to an open field and do some testing. Probably 5 times in the last few weeks, I've flown over some power lines behind my house (like I've been doing since 2013) and got the "Lost GPS" warning, followed by some erratic "pulsing" in the motors causing it to fly strangely. Power-cycle it, and it's totally fine. Trying to nail down what's causing it.

eyeonhigh · Mar 8, 2017

Mine did the same thing the other day. But I chalked it up to a low battery because it was at the very end of my flight. I put in a fresh battery and it didn't happen again.

Greg Parker · Mar 9, 2017

I have had two strange flights also in the past week and a half on a Solo that had been rock solid.

Kelly Schrock · Mar 9, 2017

Greg Parker said:
I have had two strange flights also in the past week and a half on a Solo that had been rock solid.

Strange in what way? Was it twitching like what's described here? Using Solex?

Greg Parker · Mar 9, 2017

Kelly Schrock said:
Strange in what way? Was it twitching like what's described here? Using Solex?

No twitching. More like what is described here:
Solo loosing control in Manual.

Kelly Schrock · Mar 9, 2017

Greg Parker said:
No twitching. More like what is described here:
Solo loosing control in Manual.

Ah, understood. I'm doing some testing today, combing through log files to see if there's anything weird coming from the flight controller. So far, 2 test flights, nothing erratic.

Greg Parker · Mar 9, 2017

Thanks

Kelly Schrock said:
Ah, understood. I'm doing some testing today, combing through log files to see if there's anything weird coming from the flight controller. So far, 2 test flights, nothing erratic.

Thanks for investigating.

Loner556 · Mar 9, 2017

Kelly Schrock said:
Ah, understood. I'm doing some testing today, combing through log files to see if there's anything weird coming from the flight controller. So far, 2 test flights, nothing erratic.

Author of the Solo Losing Control in Manual thread checking in. Wanted to state that I was using Solex during both flights where loss of control and twitching was experienced.

Kelly, definitely not pointing fingers by any means and I'm with you on the fact that I wouldn't suspect it to be Solex either. Something is going on though and I'm hoping we can collectively figure it out.

Both Solo's were rock solid up to this point. I'm weary to fly right now BC both times loss of control was experienced, it was on the edge of disastrous. If I'd been at altitude, it wouldn't have ended well.

yarrr · Mar 9, 2017

I also experienced the twitching today on two flights.

Both with Solex 1.3.3, one on a Samsung tablet, one on Samsung Galaxy S7E.

Flew a third flight with Solo app, and everything seemed totally normal.

The twitching (same as filmed in the OP) started, and shortly afterwards I lost GPS lock (with 20+ sats on M8N). Twitching went on for several minutes (in both alt hold or loiter). On the second flight I landed, re-armed, and took off again with the twitching continuing.

Vehicle has been rock solid for the last 6 months. Happy to share logs. Pretty puzzling.

BiggityBates · Mar 9, 2017

yarrr said:
I also experienced the twitching today on two flights.

Both with Solex 1.3.3, one on a Samsung tablet, one on Samsung Galaxy S7E.

Flew a third flight with Solo app, and everything seemed totally normal.

The twitching (same as filmed in the OP) started, and shortly afterwards I lost GPS lock (with 20+ sats on M8N). Twitching went on for several minutes (in both alt hold or loiter). On the second flight I landed, re-armed, and took off again with the twitching continuing.

Vehicle has been rock solid for the last 6 months. Happy to share logs. Pretty puzzling.

This is EXACTLY what happened to me 2 days ago. Vehicle has been fine for weeks, then 2 days ago my flight kept losing gps lock (using solex) and going into alt hold for about 10 seconds, then getting lock back. It happened often. It also seemed to occur when I clicked down the paddle to start recording video. As soon as I clicked, I would lose GPS lock, get no feedback about recording or nothing. Repeated the same thing a couple of times. Decided to land, but landing failed and solo flipped and I lost all my rotors... something is wrong somewhere in the system.... and it had to have happened recently. Whether its the firmware, the app, I dont know, but now my solo is out of commission because it was experiencing the same exact issues.

I should note I was using the mRo GPS unit as well with 21 satellites when I would lose lock.

Gelugon · Mar 9, 2017

So this would bring up the question. Is everyone experiencing this issue running the mRo gps? Any one with a stock gps have this twitching?

I haven't upgraded mine, I will test tomorrow, I need a reason to fly.

Loner556 · Mar 9, 2017

Gelugon said:
So this would bring up the question. Is everyone experiencing this issue running the mRo gps? Any one with a stock gps have this twitching?

I haven't upgraded mine, I will test tomorrow, I need a reason to fly.

Running stock GPS on mine.

droneswag420blazeit · Mar 9, 2017

Update post from Solex facebook group:

Kelly Schrock
2 hrs
PSA: Do not adjust your speed while flying!

A few people have been reporting some odd twitchiness in the way Solo flies when using Solex. There's really no way an app can make it fly erratically, except when adjusting the speed parameters while flying. Chris Lumsden found it first, described it to me, and I went out and tried it (after flying all day with no success reproducing the problem). I tried it, and BAM. Same thing. Rhythmic pulsing of the motors, getting progressively worse until it was kind of hard to land it. It also triggers a "GPS Lost" warning.

Anyway, I'm on it.

Be safe out there.