jtrout19

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GPS and AuxMag Issues when doing everything right!
« on: November 06, 2016, 07:37:13 pm »
Got GPS and MAG going last night. Went outside today and calibrate mag over oplink. All Green and my three blue bars are all centered on 0. Although occasionally I will have an axis tick a point up or down. Anyway the GPS is not seeing more than 6 satellites most of the time. Everynow and again I will get 7 momentarily just enough for everything to go green but then it ticks back down to 6. I am using a Ublox neo 6m. I use thishttps://www.rcgroups.com/forums/showpost.php?p=30987654&postcount=296https://www.rcgroups.com/forums/showpost.php?p=30987654&postcount=296 to get serial Mag and GPS.

Really frustrating as I am trying so hard to get this up and running. Quad flies great in Complimentary mode. My artificial horizon is also jerky and not level. I have performed all calibration except thermal and done them over again to make sure I did them right.

Can anyone help? Thanks

edit: GPS Protocol is DJI running at 57600
« Last Edit: November 14, 2016, 09:49:53 pm by jtrout19 »

f5soh

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Re: GPS only seeing 6 satellites?
« Reply #1 on: November 06, 2016, 07:45:56 pm »
The GPS issue you have is only related to the GPS module you use.

Attitude jerky comes generally from a not so good calibration and AuxMag orientation.

jtrout19

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Re: GPS only seeing 6 satellites?
« Reply #2 on: November 06, 2016, 08:01:38 pm »
So I read it can only pick up USA satellites. That being said do we only have 6 satellites? sometimes it wont get over 5 that it is connected to. So how Do i get the quad to arm using only 5 satellites?

I have calibrated the aux mag 3 times now in the middle of a corn field with OPlink. So whats next?


Also Mag stay green at full throttle!
« Last Edit: November 06, 2016, 08:09:54 pm by jtrout19 »

f5soh

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Re: GPS only seeing 6 satellites?
« Reply #3 on: November 06, 2016, 08:14:42 pm »
So how Do i get the quad to arm using only 5 satellites?

https://librepilot.atlassian.net/wiki/display/LPDOC/GPS+setup#GPSsetup-ExtendedGPSoptions
yes, neo6 only receive USA sats

Quote
I have calibrated the aux mag 3 times now in the middle of a corn field with OPlink. So whats next?

The calibration issue is covered in many places in forum, you should do a "calibration dance" for best results and double check the AuxMag orientation.
https://forum.librepilot.org/index.php?topic=1110.msg15449#msg15449



jtrout19

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Re: GPS only seeing 6 satellites?
« Reply #4 on: November 06, 2016, 08:41:17 pm »
I have read through that entire post, great read lots of good info. Ive included picture of my mag page in GCS. You can see the one axis that is ticked a point

settings are roll - 0 pitch -5 and yaw 0

I watched the calibration video done by Luarant? (SP?) and did exactly what he did only difference is my FC is in my quad.

If I set mode to just complimentary+mag. The artificial horizon in flight data tab is nice and stable. No jumping around!

My fix jumps alot from 2d to 3d. I cannot get a steady 3d fix?

system tab is showing PDOP in the 11's as well
« Last Edit: November 06, 2016, 08:54:23 pm by jtrout19 »

f5soh

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Re: GPS only seeing 6 satellites?
« Reply #5 on: November 06, 2016, 08:54:25 pm »
-5° do not make sense, except if mag is not level with board or you have motor mounts with tilt.

The 3 bars should still at zero whatever the frame orientation.

yes, my name is Laurent, i don't know what do you mean with "SP" ?
You can easily note the avatar in youtube and in this forum are the same.


jtrout19

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Re: GPS only seeing 6 satellites?
« Reply #6 on: November 06, 2016, 09:16:13 pm »
(SP?) means spelling i was unsure if I spelt your name right. I wasnt paying attention to the avatars to be honest. It is a extremely helpful video and I appreciate that you made it.

My value were only like 5 points or so off from all being zero. I think I may have a small bit of tilt to my gps on its staff. Not much just enough to make it where i had to use small value to get all zeros. And bars stay at zero in all orientations at this point. I think it may be the Arduino thing I made. I never had issues with satellite lock before using the thing. So I am still waiting on Sbus to CPPM converter in mail When i get that I will start using I2C mag and see if that changes anything.

jtrout19

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GPS pitching back and forth in GCS
« Reply #7 on: November 07, 2016, 07:57:52 am »
So I have solved the issue of my neo-6m not picking up more than 4 or 5 satellites. I ended up disassembling my quad and redoing all the wire. Re-Routed some, made alot shorter and doubled checked that everything was twisted. It picks up satellites very quick now. I was unable to solve the issue of the quad rocking back and forth in the Flight Data tab both model view does it and the Artificial Horizon does it as well its very slight just enough to notice it, the quad also is constantly moving in the MAP view as well. Ive played with filter settings on the accelerometer and gyro. Mag is calibrated properly per laurent's video. All bars are dead "0" In every position. I have also done the other calibrations that can be done and still have the rocking issue. Any thoughts?

jtrout19

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Re: GPS only seeing 6 satellites?
« Reply #8 on: November 07, 2016, 08:02:16 am »
Solved this issue. Basically rebuilt the quad. New wire made sure it was all twisted. and short as possible. Also re-routed wire to better areas. GPS finds sats real quick now and usually is at least 5 or 6 and gps stays green. still have issue with rocking though. Made new thread for it.

f5soh

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Re: GPS only seeing 6 satellites?
« Reply #9 on: November 07, 2016, 10:10:48 am »
Quote
the quad also is constantly moving in the MAP view

Position moving in the map looks normal.
Gps accurancy is not so well, you can expect in best cases a moving vehicle within 3/4meters.

Gps reception can be disturbed with close house/wall and echo/ghost signals.

The rooking issues comes usually from sensor contradiction, especially when vehicle is still.
https://librepilot.atlassian.net/wiki/display/LPDOC/INS13+-+GPS+Navigation#INS13-GPSNavigation-Sensorcontradiction

No need to start a new thread in different forum sections every time you have an issue, this mean also duplicate answers...
Just for information you are already the "top thread starter"
Better use the search function for a similar thread already started and maybe answered

jtrout19

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Re: GPS only seeing 6 satellites?
« Reply #10 on: November 07, 2016, 02:11:00 pm »
I do use the search function both in the forums and in google. Alot of times i have issues not finding what i need because i am not wording something correctly. So i apologize if i have asked duplicate questions about things. I read through the link you posted. And found this statement on how to fix my issue.

"To fix this, the variances should be adjusted by increasing or decreasing the variance of one of the affected sensors as well as fixing the cause for the contradiction (for example an incorrect magnetometer calibration)."

Since i have double and tripled check the calibrations the only thing left would be to increase or decrease the variance of the sensors. How is this done?

f5soh

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Re: GPS only seeing 6 satellites?
« Reply #11 on: November 07, 2016, 02:16:52 pm »
Never modified the EKF defaults settings here.

Post your config file

jtrout19

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Re: GPS only seeing 6 satellites?
« Reply #12 on: November 07, 2016, 02:23:56 pm »
Ok thank you for helping. I would be lost without this forum.


f5soh

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Re: GPS only seeing 6 satellites?
« Reply #13 on: November 07, 2016, 02:44:39 pm »
Strange AuxMag Rotation, try to mimic the rotation and solve the final result:
Code: [Select]
<field name="BoardRotation" values="175,180,180"/>
Redo the calibration doing a "Calibration dance", scales are not consistent:

jtrout19

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Re: GPS only seeing 6 satellites?
« Reply #14 on: November 07, 2016, 02:53:58 pm »
Ok I will do this particular one. I did your method in your video. I played with those valuse for about an hour last night......if I set everything to 0 the blue bars are only off 1 or 2 points. I remounted GPS unit last night as well. The mounting tape that is came with did not hold it level on the mast it was pitched up about 10-15 degrees so I used a different mounting tape and now it is level with the quad. I will be right back.