[TMGsi]

I'm using a modified MinimOpOsd firmware. Some features were discarded to free space and I've coded new ones that I felt being more useful. I've always intended to make it available to LP community, and I plan to do this in near future. What stopped me till now was that the default OSD Config Tool 2.1.3.0 is not really compatible with it. Charset differs, some fields have totally different layout and meanings.
I've recently had some free time and dedicated it to match the OSD Config Tool to my firmware. I'm almost at the final, and hope in a week or two to upload the new config tool, charset file and MinimOpOSD hex files (for RevoFC) for quadcopter and plane use. There is also a version dedicated to quadcopter (w/ CC3D) use, with voltage sensor connected to MinimOSD.

Man, that's cool. Success in your work. This is going to be very useful.

[TMGsi]

https://photos.app.goo.gl/bhZAeUHs8T2PJU4V8

[TMGsi]

I don't know how to post a photo

[TheOtherCliff]

Either upload/attach the photo file to your post or provide a direct link to the photo file such as ending in ".jpg".  The link you posted was to a web page that had the photo on it.

Looks like you got thermal calibration done successfully.

I suggest that you redo the other calibrations.  I recall that thermal calibration changes them a little and they should be redone.

[TMGsi]

photo upload test.  Best gps location for me.

[TheOtherCliff]

That should work OK if it is configured to use only the aux mag.

It might be a little top heavy.  It might need a little more careful tuning, but should work.

Is the mast really good and stiff or does it wobble a bit?  Loose and wobble might cause issues.

[TMGsi]

after having successfully completed the thermal calibration.  the drone was left with some disturbance on the yaw. 

the drone takes off normally, but when I clicked the key to positionhold the drone makes a very strong movement on the yaw.

 when switching to any flight mode it spins on the yaw.

 and I did all the calibrations after doing the thermal calibration.

 after that i ask,

do you need to calibrate the thermal?  instead of improving after calibrating it got worse. 

my version of librepilot is 16.09.
 will upgrading to the latest version of librepilot improve?

[TheOtherCliff]

after having successfully completed the thermal calibration.  the drone was left with some disturbance on the yaw. 

the drone takes off normally, but when I clicked the key to positionhold the drone makes a very strong movement on the yaw.

 when switching to any flight mode it spins on the yaw.

 and I did all the calibrations after doing the thermal calibration.

This may be a result of setting VtolPathFollowerSettings->YawControl 
It turns to point in the direction that it moves for the little motions in PH

Does it spin constantly at a constant rate or does it spin say 30 degrees and hold there or does it spin randomly?

The following will not help if it spins randomly.

One reason would be if the GPS / compass was rotated a little.  You could rotate the GPS / compass a little to correct it or even easier, you could change the Attitude->Magnetometer->orientation->Yaw.  One way should make it worse and the other way should make it better.

Another reason is if any power cables are not twisted.  Sometimes you might install a different battery or a battery without twisted cables and you get an electromagnetic field when you draw current in flight.

Did you use any yaw trim?  Basically, transmitter trims should always be centered.  With everything (drone and transmitter) powered up as for flight, and GCS USB plugged in, you can look at input page to see if received yaw value equals neutral as shown by GCS yaw value.

do you need to calibrate the thermal?  instead of improving after calibrating it got worse. 

No.  The only reason you might need to redo thermal calibration is if the FC got moved during thermal calibration.  That is the reason for putting a weight on top of the FC.

my version of librepilot is 16.09.
 will upgrading to the latest version of librepilot improve?

No.  Very probably not.

[TMGsi]

that's right.

  what was causing the yaw disturbance was the change in the yawcontrol.  (I thought he would do it only on RTB, but he does it in all flight modes) and I also thought it was a smooth and precise movement. 

however it was a very strong movement to the point of making the drone lose control. 

I went back to the default value and solved this problem.
 I will be without turning when I enter the rtb (although I can turn manually) of all my problems this is the least important.

[TMGsi]

I saw a video and in the video he managed to leave all axes at zero.
https://youtu.be/qLsd4O75N9o



 I can't get it to zero.  (in the video he changes the roll to 180 and yaw to -90) I don't need to make this change,

what I found interesting was that every movement he made the axes returned to zero)

what do you advise me to do? 

a note: the drone does not stay and the positionhold in the DJi drone standard, but I can fly and make a longrange safely.

 what I'm looking for is a fine adjustment.  see a picture of how it looks in mine.

[TheOtherCliff]

You are using a DJI/Naza GPS/mag mounted upright with the arrow pointing forward.  This needs to be 0,0,0.

He was using a mag board that normally needs to be either 180,0,180 or 0,180,0 (they are the same rotation) and he had it mounted with the arrow pointing sideways.

Generally, aligning it to be level and pointing forward carefully by eye is good enough.  Then for DJI and OP GPS/mag orientation is set to 0,0,0 and for other it is set to 0,180,0.

A good way to test is in Velocity Roam.  When you press the pitch stick forward does it go straight forward or a little sideways?  If it is consistently a little sideways in the same direction (in more than one flying field) you might adjust the aux mag yaw orientation a little if it bothers you.

[TMGsi]

I have done it with USB cable, but I degaussed (demagnetized) the USB cable end and used flight battery / ESC power at 5.5 to 6 volts (more than USB power) to make sure it used ESC power and not USB power and used a 3 meter USB cable with a laptop all outdoors.

I haven't tried that yet.
I don't understand how to do this.

What I understood was: Did you cut off the usb power via the computer and solder the esc power supply wire?






I'll buy a 2m or 3m usb cable and try.


I use librepilot on a tablet that runs windows and android. On windows librepilot installed, so what powers the tablet is a voltage of 1 cell of lipo battery. (so I think the disturbance transmitted to the compass is less on this tablet). This thought of mine is not very certain because the drone is not yet excellent in positionhold, it was good, not excellent. (and my new gps that is not enough for me to test soon)

[TMGsi]

I made a representation in paint, what did you do?

[TheOtherCliff]

To summarize: Use "aux only" mag setting.  Use a 2-3 meter USB cable, outdoors, away from metal buildings, tanks, cars, watches.  Do not set model on ground once you start.  Hold it in the air, away from USB cable as much as reasonable.  Since you are using "aux only" mag, don't worry about demagnetizing the USB plug or the ESC/BEC voltage or cutting or soldering.

The rest of this post is details, and after I wrote it, I realized that simple summary was more important. 

I have done it with USB cable, but I degaussed (demagnetized) the USB cable end and used flight battery / ESC power at 5.5 to 6 volts (more than USB power) to make sure it used ESC power and not USB power and used a 3 meter USB cable with a laptop all outdoors.

I don't understand how to do this.

What I understood was: Did you cut off the usb power via the computer and solder the esc power supply wire?

The metal in the micro end of the USB cable that plugs in the FC might have slight magnetism.  Being so close to "On Board" mag during calibration, the magnetism might make the calibration bad.  I have a soldering "gun" with big electro-magnet that I use for de-magnetizing.  BUT: You can skip the USB end de-magnetizing if you are using "aux only" setting, because it does not matter if the "on board" magnetometer is calibrated badly if using "aux only".

USB standard is 5V, so your tablet has a circuit to increase the voltage from 1 cell voltage.  The biggest computer or the smallest phone would all thus be equal for USB power.  A 2-3 meter USB cable should be OK to do calibration with really any computer.  I prefer 3 meter...

FC has diodes in it so that it will use either 5V USB power or 5V power coming from ESC.  Which ever has the highest voltage will be used, so I used 5.5V ESC power to be higher than 5V USB power (electro-magnetism does not depend on voltage, only on current and the FC regulators are linear...).  This is to make sure that FC power uses the same traces on the FC board during calibration (ESC power) that it uses during flight.  This is overkill.    This is really about getting "on board" magnetometer calibrated well.  AGAIN: If you are not using "on board" mag, you can probably not worry about the voltage.  You still need ESC power though.  The FC circuits do not let USB power come out to any ports (such as GPS/mag on Flexiport / Mainport).  Only ESC power comes out to ports.

What I understood was: Did you cut off the usb power via the computer and solder the esc power supply wire?

I simply made sure the ESC power voltage was higher so that it would be used.  No cutting or soldering.

You raise a very good method (to make sure it uses ESC power) that I had not though of.  Simply cut the + power lead in the USB cable.  Only the + lead, usually pink.  Leave the other wires connected.  AGAIN: This mess can be skipped if you are using "aux only" mag and don't care about "onboard" mag calibration.

[TMGsi]

understand,
I will not worry about demagnetizing the usv cable, as it is for the onboard compass. It was well explained.

so much so that I posted a photo showing the status of the compass, onboard (5.5%) and auxmag (0.4%)
a very big difference between them.

Only my axes (x, y, z) that do not return to zero, in the photo it shows them too. (and I think my positionhold is not perfect so the axes have a little problem with zeroing)


But, I will try with the 3m usb cable.