Altitude GPS
« on: March 08, 2016, 01:36:07 pm »
Dear,
I would like control altitude copter . We are develop our own GPS system, accuracy. It's generate all packets like a GPS UBLOX.
But I wan use only the altitude of our GPS et disable a barometer. It's possible to do this ?
Thank you very much for your help
Best Regards

Re: Altitude GPS
« Reply #1 on: March 08, 2016, 05:28:38 pm »
Compared to baro, GPS altitude is much less accurate in the short time frame, but more accurate in the long time frame, so we have not tested GPS flight without baro.  There are EKF settings in GCS -> System -> EKFConfiguration that could be adjusted to stop using baro, but you need to know how to tune an EKF.  A programmer with a math degree might do it.  Another way would be to get source code, and make baro sensor code always return 0 altitude, but even that might need EKF tuning.

f5soh

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Re: Altitude GPS
« Reply #2 on: March 08, 2016, 08:09:03 pm »
Hi,

I already answered to the same question here:
https://forum.librepilot.org/index.php?topic=1020.msg7343#msg7343

Do you have setup a build environment and look at code ?

Laurent

Re: Altitude GPS
« Reply #3 on: March 09, 2016, 11:25:59 am »
Hi TheOtherCliff,
Thank you a lot for your quick reply. I will try all your suggestions.
Best regards

Re: Altitude GPS
« Reply #4 on: March 09, 2016, 01:29:12 pm »
Hi Laurent,
I read "./flight/modules/StateEstimation/filteraltitude.c" file.
I m agree with you,if i set a "kp Baro" to 0, no data from baro will be use. I will try it so quick.
I m waiting a Revolution Flight controller.
Than you a lot

f5soh

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Re: Altitude GPS
« Reply #5 on: March 09, 2016, 02:46:04 pm »
ok :)

Please note the "Revolution" board doesn't exist, its a Chinese / commercial invention.

CC3D or Revolution are two different boards.

Re: Altitude GPS
« Reply #6 on: March 10, 2016, 01:06:06 pm »
Hi Laurent !
Thank you for your message about revolution card. Where I can buy the real CC3D, not a chinese copy ?
because I see in www.unmannedtechshop.co.uk, the CC3D is not available, I think hobby king is a chinese copy too.



f5soh

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Re: Altitude GPS
« Reply #7 on: March 10, 2016, 02:01:45 pm »
CC3D is a basic board without baro, mag or any nav features.

All boards are clones.
Some Revolution (the one with baro/mag) boards with yellow/red/maroon output connectors do not follow original design.


hwh

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Re: Altitude GPS
« Reply #8 on: March 10, 2016, 04:21:18 pm »
If you want to do experiments involving gps you don't want a cc3d, you want a revolution board.   The cc3d doesn't use the gps for any flight modes, it just passes it along to gcs in telemetry.

All currently available boards are clones, cc3d hasn't been made in several years, revo in a year or so, and the revo nano sometime last year.

The Revolution you were talking about is a revolution clone.  They just put the cc3d in the name because people run searches for cc3d more than revolution.  The easiest way to tell the cc3d from revo is look at the cpu chip, cc3d is a STM32F103 and the revo class ones use STM32F405 or 411 chips. On all the Chinese boards quality varies a lot.  Many of them have the wrong capacitor on the voltage regulator and that creates noise on the power bus that interferes with the baro sensor.   The fix is easy and documented in the forum.

jbarchuk

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Re: Altitude GPS
« Reply #9 on: March 11, 2016, 12:23:37 am »
...the real CC3D, ... I think hobby king is a chinese copy too.

Right. And only IBM ever made a 'real' PC. ;) I'm not going to get into the political and semantic topics.  ;D

At one time HK even did the right thing and contributed back to OP, then later threw OP under the bus the same as they did Rolf Bakke.

Regardless. [sigh]

I got two HK CC3D early on and inspected the snotrag out of them before I used them. (I have a military level electronics manufacturing background.) They were very well and properly made, as good as a 'real' CC3D. ;) I can only hope they still make them to the same level of quality.

Re: Altitude GPS
« Reply #10 on: March 14, 2016, 05:37:14 am »
Biggest problem lately is that clones often have substitute parts.  The parts themselves may be OK, but for instance a substitute voltage regulator needs a different capacitor and without that change, puts bad noise on +3.3V which makes the baro sensor unusable.

Re: Altitude GPS
« Reply #11 on: March 21, 2016, 08:19:03 am »
Hi all !
I made some tests with Revolution controller and "librepilot" code onboard on DJI550 frame. It's very very nice fligh.
I some problem to work a gps DJI on this card. On GroundControl software, the GPS blink between good and bad. I don't know Why.
I m searching a solution. I genere RS232 3.3V frame. Maybe a frequence all frame.
GPS Data : 250ms,
Compass Data : 30ms
Version Data :2s
Have a good day

Re: Altitude GPS
« Reply #12 on: March 21, 2016, 02:10:21 pm »
I found the problem. this is a number of sequence. I must set one time only.
Now it's Ok.
I have a another problem. My frame DJI Compass don't work. It's a take the compass onboard then in Configuragtion tab, the paramters are
Mag usage : AuxOnly
Mag Type : DJI
I will check all paramter again
Have a good day

hwh

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Re: Altitude GPS
« Reply #13 on: March 21, 2016, 03:00:58 pm »
I looked through your posts but couldn't figure out exactly what gps and mag sensor we're talking about or how they're hooked up.

The DJI compass module supported is part of the DJI GPS and connects via the same cable.  Other mag sensors that are based on HMC5883 are supported via I2C.  I'm not sure what a frame DJI compass is or how you're connecting it to the revo.

Re: Altitude GPS
« Reply #14 on: March 21, 2016, 03:09:32 pm »
I would like use only DJI compass and disable compass onboard. Normally it's possible by choose "AuxOnly" on Mas usage (Configuration ->Magnetometer tab).
But the Mag source display : "Source invalid"
I don't know why./ Morever when i move a DJI compass/GPS, compass don't move on software but when i move CC3D then value of compass changed.