Solex causing Solo to twitch

[Kelly Schrock]

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.

Good news: I did a bunch of testing today with the app, tried doing exactly the same sorts of things I had done in the past when I got the "Lost GPS" warning (which some people had mentioned), no luck. But a guy on the Facebook group found that if he adjusted his speed while he was flying, he would get the twitch. I took my rig out and tested that, and was able to reproduce it like clockwork. All I had to do is fly, adjust speed, and the motors would start to pulse, getting worse and worse until it was kind of a handful to land. Power-cycling the Solo puts things back to how they're supposed to work, but adjust the speed again, and bam, it does the exact same thing. As it turns out, the fix appears to be pretty easy.

1.3.3 was the first (and last) version of Solex to ship with an updated Dronekit library (3.2.0). Since day one, I'd been maintaining a custom branch of Dronekit based on 3.0.0. I didn't notice any problems with it, but I thought it a good idea to upgrade to 3.2.0 to catch any bug fixes that might have gone in. So I merged 3.2.0 into a branch based on my custom branch. From the start, it acted strange: I had to fix a bunch of things that stopped working (signal indication, double "connect" events when connecting, total failure of Cable Cam due to a "message queue length" feature that was added, etc) I worked for about a week to get it working reliably, and the first time I noticed the loss of GPS was when I was running it. I thought it was just a coincidence at the time. I actually added an EKF widget to the new version of Solex thinking it was something with EKF. I also noticed that when changing speed in Guided mode (e.g. on the Guidance UI) that it would lose GPS most of the time, followed by the twitch. I downgraded to 3.0.0 and tested it doing the same things many times, and no problems at all. Switch back to 3.2.0, and I could get it to happen every single time.

So, there'll be another round of tests tomorrow morning, then 1.3.4 will come out with an old version of Dronekit.

Thanks,
Kelly

 

[Kelly Schrock]

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.

First time for everything (e.g. replying to myself). The above is BS. I posted something in Solex causing Solo to twitch about this. Turns out there's an issue with DroneKit 3.2.0 that was included for the first time in Solex 1.3.3. It's not going to be in 1.3.4.

 

[Loner556]

snip

So, there'll be another round of tests tomorrow morning, then 1.3.4 will come out with an old version of Dronekit.

Thanks,
Kelly

Kelly, thanks for the continued work on Solex. Glad the problem was figured out quickly.

 

[Frank Foster]

This is getting interesting!

 

[Greg Parker]

Kelly has 1.3.4 out now with a number of fixes and improvements mentioned. It is nice to see someone so responsive to fixing issues as they are reported.

Thanks again Kelly!

 

[Bilge]

Kelly, he is the man......tipping my hat to you.....thanks again for the quick fix......

 

[pyrate]

Wow would not have thought that possible. Great work.

 

[jcar]

When you guys move those sliders you are changing the PID settings and yes it will twitch. Suggest you make those changes before you take off.

 

[Kelly Schrock]

When you guys move those sliders you are changing the PID settings and yes it will twitch. Suggest you make those changes before you take off.

The problem here was that it kept twitching and wouldn't stop until it was landed and powered off/on again. Thinking it's some kind of ACK from the copter that isn't being handled in the same way by DroneKit 3.2.0, but I haven't had a chance to test that out yet.

 

[mike sember]

Hey guys, glad you are fixing the twitching issue. I can't wait to get solex when my tablet comes in. It sounds like you figured out the twitching, but what about the pulsing of the motors? I have been experiencing the pulsing of the motors latley on a solid solo for the last year. It has not been flying all that bad, but the pulsing of the motors scars me a little. I first thought it was a glitch after i downloaded the new autocopter firmware, but it seems like other people have this problem and I'm sure not everyone has that update.

 

[Kelly Schrock]

Hey guys, glad you are fixing the twitching issue. I can't wait to get solex when my tablet comes in. It sounds like you figured out the twitching, but what about the pulsing of the motors? I have been experiencing the pulsing of the motors latley on a solid solo for the last year. It has not been flying all that bad, but the pulsing of the motors scars me a little. I first thought it was a glitch after i downloaded the new autocopter firmware, but it seems like other people have this problem and I'm sure not everyone has that update.

FWIW, the twitching was the pulsing of the motors. It made the Solo fly "twitchy". As far as the pulsing relates to Solex, it's fixed in 1.3.4, released Friday.

 

[nvpowerdoc]

Twitch is back??? Can it be?

I hate resurrecting an old thread, but I recently completed the upgrade to OpenSolo 3.0.0. Prior to the Firmware upgrade, my Solo did not exhibit the twitching issues described previously in this thread (50 Plus flights).

Currently running Solex Version 1.7.0 on nVidia Shield, Solex reports AutoPilot 1.5.4, controller 3.0.0, Vehicle 3.0.0, Gimbal 1.3.6.

Upon finishing the Firmware upgrade, I did the usual Calibrate IMU and Calibrate Compass routine, and flew a full battery without the Gimbal installed (figured no need to risk a Gimbal and Hero 4 Black). Solo seemed to fly fine. Next, I installed the Gimbal and GoPro and repeated the IMU and Compass Calibration. Solo is very twitchy with the Gimbal and GoPro installed. What have I missed that could be causing this?

Also, sometimes when I open the Solex Menu, the IMU and Compass Calibration items are grayed out. Also, is Solex / Solo fully downloading all parameters if it is reading 98% and 512 parameters?

Also, from my DIY Pixhawk days, I avoid changing parameters (like speed, yaw, etc.) while the Solo is flying. It seems like something is wrong with the PID loops. Any help or guidance would be great.

 

[Kelly Schrock]

Twitch is back??? Can it be?

I hate resurrecting an old thread, but I recently completed the upgrade to OpenSolo 3.0.0. Prior to the Firmware upgrade, my Solo did not exhibit the twitching issues described previously in this thread (50 Plus flights).

I seriously doubt the twitch is the same thing as it was back then (December 2016?). That was due to me switching to a version of DroneKit that was doing a lot of strange things, including the twitch-inducing method of writing parameters. I switched back to the version of DroneKit I was using before, and I'm still using it.

 

[brig57]

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.

 

[brig57]

I had same thing happen to my solo this weekend. It was about 1 min. Into flight, about 25 ft altitude. It took 2 flips forard and dived to the asphalt. Weird part was it appeared 2 props were off before impact, because the threaded stud on the motor on both were damaged, the other 2 props were still on. But I have been having the "twitch", for about a month on solex

 

[brig57]

I had same thing happen to my solo this weekend. It was about 1 min. Into flight, about 25 ft altitude. It took 2 flips forard and dived to the asphalt. Weird part was it appeared 2 props were off before impact, because the threaded stud on the motor on both were damaged, the other 2 props were still on. But I have been having the "twitch", for about a month on solex

PS, I have the M RO GPS also

 

[Kelly Schrock]

Wow! Well, I will investigate and see if I can reproduce it. That was eliminated the first time by reverting back to my custom DroneKit build over a year ago, and I hadn't seen it since. But if it's back, I'll eliminate it again.

 

[nvpowerdoc]

Wow! Well, I will investigate and see if I can reproduce it. That was eliminated the first time by reverting back to my custom DroneKit build over a year ago, and I hadn't seen it since. But if it's back, I'll eliminate it again.

Sounds awesome. Can't say Solex is the cause, but wondering if it's something in the Copter and Transmitter firmware upgrade since I just completed that with OpenSolo 3.0.0. I have a second bird to re-assemble, so it will be interesting if it exhibits the same "twitch". Unfortunately, I did the OpenSolo upgrade on that bird too.

 

[nvpowerdoc]

Sounds awesome. Can't say Solex is the cause, but wondering if it's something in the Copter and Transmitter firmware upgrade since I just completed that with OpenSolo 3.0.0. I have a second bird to re-assemble, so it will be interesting if it exhibits the same "twitch". Unfortunately, I did the OpenSolo upgrade on that bird too.

So a little update, I re-assembled Solo #2. Did the standard IMU and Compass calibration prior to flying Solo #2. It's flying nice and smooth (both with and without a Gimbal) and is based on a firmware upgrade using SD Card Images of the SD cards from Solo Controller #1 and Solo TX #1 (of which was done using the normal OpenSolo 3.0.0 upgrade routine via Wifi).

Then I took the Gimbal off Solo #1. Performed the IMU and Compass calibration (again). It flies OK without the Gimbal, but is a little sketchy (definitely not twitchy like with the Gimbal). Solo #1 and #2 are both stock units with new props and never been crashed (#1 probably has 100+ flights on it). So I don't think the twitch issue is a Solex derived issue. Going to put another gimbal back on Solo #1 and see if the twitch comes back.

Is it correct that once you put a Gimbal on the Solo, that the IMU and Compass calibration options become grayed out in the Solex App? Is this normal, and is there no reason to perform a compass calibration once the Gimbal is installed (in that it has magnets in the servos and whatever other ferrous components might be in the Gimbal)?

 

[brig57]

Wow! Well, I will investigate and see if I can reproduce it. That was eliminated the first time by reverting back to my custom DroneKit build over a year ago, and I hadn't seen it since. But if it's back, I'll eliminate it again.

Sounds great, thanks!!
When I get it back together, I'll let you know how it goes.
Thanks Again, great job!!!