[zukenj]

Attached is a picture of the DJI clone GPS. I use to have an M7 and to set it up correctly i have the roll = 180. After i connected the DJI clone I have to  change the roll to 0. Does the DJI have the mag position on the firmware?

Sent from my SM-N900P using Tapatalk

[Mateusz]

In the attachment I marked chip which is probably magnetometer, it should have symbols L883 on it.
As you can see it has some unusual 45-ish degree rotation in yaw. However I don't know what exactly value in which direction.
Best is try different values and then check scopes if both magnetometers show the same patterns.

[Jhinta]

Attached is a picture of the DJI clone GPS. I use to have an M7 and to set it up correctly i have the roll = 180. After i connected the DJI clone I have to  change the roll to 0. Does the DJI have the mag position on the firmware?

Sent from my SM-N900P using Tapatalk

Q, did you test GPS ?

Verstuurd vanaf mijn LG-D855 met Tapatalk

[zukenj]

Jhinta,

Thanks for your response.

I see what you mean with the mag angle. But the chip is pointing to the front like the arrow next to it.

Yes, GPS worked fine. I got 7/10 Sats in side. So far the issue is the mag. I need to figure it out.

[Jhinta]

Attached is a picture of the DJI clone GPS. I use to have an M7 and to set it up correctly i have the roll = 180. After i connected the DJI clone I have to  change the roll to 0. Does the DJI have the mag position on the firmware?

Sent from my SM-N900P using Tapatalk

Q, did you test GPS ?

Verstuurd vanaf mijn LG-D855 met Tapatalk

Good to know , where did you buy it ?

Verstuurd vanaf mijn LG-D855 met Tapatalk

[Mateusz]

I see what you mean with the mag angle.

By default AuxMag rotation is 0,0,0 because this matches how OPv9 GPS Platinium had L883 magnetometer installed.
However, each manufacturer can put magnetometer in different orientation, so you need to tell software how it is oriented with respect to internal magnetometer.
You don't know if its +45 or -45 deg and from what to substract it. For example GPS magnetometer could be flipped up-side-down or yaw rotated 180 deg with respect to FC magnetometer, then it could be additionally rotated 45deg. I think testing +45 or -45 might not be enough.

Easiest is to look how L883 is oriented on Revo and figureout yaw,roll,pitch for GPS one. Then verify by right clicking on scopes, adding AuxMag curves and checking if they behave the same.

I also saw people entering some strange values like 11, 22 etc.. that is most likely incorrect. If you have everything aligned well, both boards are flat and on the same "plane" (if you imagine such a plane), then values should be +-90/180/270 or +-45 deg in exotic situations like yours. I doubt any manufactures would install magnetometer with +11 yaw rotation Just keep that in mind, cause lots of people tend to enter such strange values (don't).

When you install GPS, first time you need to let it run on clean sky to update almanac. This "battery" is not a battery, it's super capacitor. It lasts up to 6-7 hours after charging.
So before first flight let it collect satellites for 15-20min, then you have ~6h up to date alamanac when you disconnect battery.

Another thing good to know, is that VTX (video transmitter uses 5G signal) because it's noisy it can cause spikes in GPS position. It's good to keep VTX antenna far from GPS antenna, or at least VTX antena radiation pattern away from GPS. Another case of spikes can be multi-path reflections (if you use patch antenna) from buildings/walls.

GPS has it's own Extended Kalman Filter engine in the metalic box (Ublox) module. It has some filters and calculates position but if you feed bad signal from antenna it may also produce shitty estimates and jumps in position.

Sorry if too much information, just keep it in mind when building.

[zukenj]

Mateus,

Thanks for your reply.

Is not too much info, This is the 3rd GPS I set up. I know that the numbers can't be 11 or 22 or 30, they must be in 45 degrees. 0, 45, 90, etc.
As I mentioned, in my old GPS it was Roll 180 and in this one for the bars to come to 0 I have to set all Pitch, roll and yaw to 0. and that is why, I don't get it. If you see the picture the Mag will be facing down, so it will be roll 180.


I don't know if this make sense?

[zukenj]

I got all mags green.

[TheOtherCliff]

Mag green doesn't have anything to do with rotation. 

All DJI GPS use 0,0,0 for mag rotation.  The 45 degree mag chip is because the board is mounted 45 degrees in the case so that a corner points forward, not a flat side.  Also there is a processor in the DJI GPS and that processor can rotate the mag if it is coded to do so.  Just remember that all DJI GPS use 0,0,0 for mag rotation.

Of course that 0,0,0 can be different if you mount the GPS so that it sits at an angle during fixed hover.

There usually is an arrow on a GPS that has a mag and that arrow says what direction is forward.  With authentic DJI Naza GPS, the cable actually comes out the front of the GPS because the GPS is usually mounted in back of the copter.  With clone DJI Naza GPS the cable usually comes out the back of the GPS (at least the ones I have this is true).