Solex causing Solo to twitch

[nvpowerdoc]

So I wonder if differences in the Compass Offset Parameters can be contributing to the twitch / sketchy flight. I've done the Compass Calibration on both Solos (in an open area, free of metal objects, like keys in pockets). I recall from my DIY Pixhawk 1 / PX4 days (and Naza V2 for that matter) that compass offset matters.

In reviewing some of the compass parameters, some of the offsets are not the same (very different like COMPASS_OFS2_Y & _Z, and COMPASS_OFS_X is "+" on one and "-" on the other). I'll have to dig through the parameters description list as one compass is in the flight controller, and the other is near the battery (if I understand it correctly). Of the parameters images below, Solo1 (top) is the sketchy bird and Solo 2 (bottom) flies rock solid.

 

[Pedals2Paddles]

A few things while I have a few minutes....

• Taking the gimbal on and off absolutely requires a compass calibration. You're changing the sources of magnetic interference that are attached to the aircraft, and therefore the compass will need to be re-calibrated. Many people don't bother, but it is is required for proper stability and navigation.
  
  
• Taking the gimbal on and off does not require accelerometer calibration (AKA Level Cal, AKA IMU Cal). It has no impact on that.
  
  
• The Solo's default tuning parameters (AKA PIDs) that are baked into both the stock ArduCopter firmware and the Open Solo ArduCopter firmware were done with the gimbal attached. If you take the gimbal off, it will change the weight, and therefore the power to weight ratio, and therefore the tuning requirements. This will be most noticeable in high speed, high angle maneuvers. It should not be something that causes a crash, it just won't fly as smooth.
  
  
• A Solo falling out of the sky in flight will not be caused by a problem with the Solex, SidePilot, 3DR, Mission Planner, or Tower apps. That is virtually impossible. The most likely is a mechanical or electrical failure on board the copter.

 

[nvpowerdoc]

Can't speak for others, but yes I did re-perform the Compass Calibration after installing the Gimbal (knowing that other magnets - servos - and metal were added to the Solo). However, at times, Solex (just happens to be the interface I'm using) has had the IMU and Compass Calibration options greyed-out. I thought this was odd.

I'm going to setup both Solos with the same configuration (Gimbal installed) and perform the Compass Calibration in the same location (I have an acre of dirt in my back yard with no structures / metal around). I am most curious about the Compass Offset numbers, so it will be interesting to repeat the process and see what comes about.

Thanks!

 

[Pedals2Paddles]

The options being greyed out in Solex are simply an issue with the application properly detecting the Solo. @Kelly Schrock has it setup such that it will not offer options that do not apply. It is not an indication that something is wrong, it's just a communication and recognition issue. Usually when that happens, force closing the app and rebooting everything seems to clear it up.

 

[nvpowerdoc]

The options being greyed out in Solex are simply an issue with the application properly detecting the Solo. @Kelly Schrock has it setup such that it will not offer options that do not apply. It is not an indication that something is wrong, it's just a communication and recognition issue. Usually when that happens, force closing the app and rebooting everything seems to clear it up.

I'll keep that in mind.

 

[swaggy]

a little late here, but just wanted to ask a question: will changing the speed sliders in the stock Solo app cause the drone to twitch as well?

 

[brig57]

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

Kelly,
Just to be safe, I've never had a wreck before. Tell me what is the best way to download the log from the solo to give me a clue of what happened. In case it is something else I would hate to put it all together and it happen again but I have never downloaded any files. Could you give me a recommendation of the best way to do that and read what I get out of it?

Thanks in advance

 

[blahdc]

a little late here, but just wanted to ask a question: will changing the speed sliders in the stock Solo app cause the drone to twitch as well?

I happened to adjust my speed (max) during the flight and later noticed the Solo was jittering/twitching when hovering. This was even after a battery swap.