New Dual Magnetometer Option

Mike Mac July 25, 2014 at 4:40pm

I finally got all the dual sensors and dual GPS working. The latest Mission Planner has all the tools to calibrate and display everything. This is with the latest non-beat airplane firmware. You can get dual GPS, Compass, Accelerometers, and gyros.

Also did a couple of Autotune flights and now have a nice flying airplane with plenty of redundancy.

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Mike Mac June 25, 2014 at 3:05am

I have asked on several forums but none of the developers will respond. You would think that the person that wrote the code would have an idea on how they intended them to be calibrated and used. Maybe they are working on new code – who knows?

I would be nice to have some sort of a clue from one of the developers.

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ausdroid June 25, 2014 at 12:01am

Anyone have a further up date on calibrating both compasses?

gervais June 7, 2014 at 10:13am

Happy, that someone else is interested, asked this almost one month ago:

http://ardupilot.com/forum/viewtopic.php?f=100&t=7758

Seemed not to be too important, although I ve read about a IRIS crash, where some of the devs suspected (at first) that it happened because of a failure of the external compass and wrong direction of the internal one

"My hypothesis is that it was calibrated using the external compass but for some reason switched to the internal compass (possibly damaged wiring) for this flight. When the vehicle attempts to tilt towards home it tilts in the wrong direction because the internal compass is mounted opposite to the external one."

Source:

Discussion

Mike Mac > gervais June 7, 2014 at 5:07pm

I see that the mission planner and latest firmware now shows two sets of compass calibration and orientation parameters so it looks like the logic is in the firmware. I have external compass connected so now I need to figure out how to activate both at the same. I don't see a parameter to activate dual compass. It's probably there but with no documentation it's I'm at a loss?

　

That would solve the problem when the external compass has a broken wire or some other failure. The internal compass will take over with it's own calibration and orientation settings. I guess we will have to wait for some of the developers to check in and give us a clue.

　

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- gervais > Mike Mac June 7, 2014 at 11:49pm
  
  Btw. From the threads linked above, I figured, that Dual Compass is activated by DEFAULT. Internal is used automatically when external doesn´t work. (At least at PIXHAWK, where you don´t need to cut a trace)
  
  Whats not described or working (or is not intended) is the calibration at the same time.
  
  Until now,the proposal is to disconnect the external, do the calibration, copy the values in the field of the second compass and repeat the calibration with the external compass connected.
  
  This procedure leaves out COMPASSMOT, which confuses me, since the EMI related influence differs from internal to external. At least at my copter.

Mike Mac June 6, 2014 at 7:46am

Also is it possible to use the internal compass and one external compass or does it have to be two external compasses?

iskess > Mike Mac June 6, 2014 at 2:22pm

One has to be the internal one.
- Mike Mac > iskess June 6, 2014 at 2:37pm
  
  Thanks for the reply but where are the setup instructions?
  
  I have a Pixhawk and external compass so how do I activate and calibrate both of them?
  
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  - iskess > Mike Mac June 7, 2014 at 3:01am
    
    I don't know. Please post here when you figure it out, I'm have gotten to that yet.

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New Dual Magnetometer Option

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