f5soh

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #90 on: April 27, 2016, 06:07:10 pm »
Looks ok, keep in mind this is raw data from Baro sensor without filtering.

(Moved to the appropriate thread)

hugges

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #91 on: April 27, 2016, 06:21:22 pm »
Thank you but what do you mean with out filtering ,where will the filtering come from
Sorry i am  new to this copter building

f5soh

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #92 on: April 27, 2016, 06:33:07 pm »
The filtering allow removing the spikes.
The BaroSensor.Altitude is raw from sensor, just computed altitude using the pressure measured.

This data is filtered later in the process.

MGR17

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #93 on: May 06, 2016, 04:00:14 pm »
Hi, I have just found this excellent forum and hope you can help.

with the Revo static my barometer is showing 3m with a 0.6m variation, however it hardly registers pressure change at all ie possibly 0.5 metre change for 4 metre actual change in height.  Also the vertical speed indicator does not move when the Revo is raised/lowered.  I have opened the plastic case, removed the foam and blown on it and again no change. My question therefore is removing D9 likely to help or is that just to reduce fluctuations.
I have also been trying the GPS functions with little success and wondered if  they need a working barometer to function.
I have moved the Revo away from power lines and the magnetometer traces remain  steady when full power is applied satellite reception also appears good.

Any suggestions would be much appreciated.

f5soh

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #94 on: May 06, 2016, 04:38:14 pm »
Hi, welcome.

Whats "D9" ?
The issue you can see with regulator is quick changes / jumps.
value that oscillate within 0.6m is fine.

For long / slow changes in altitude this can be related to weather change or thermal drift.
You can minimize the thermal drift effect doing the thermal calibration.

https://librepilot.atlassian.net/wiki/display/LPDOC/Sensor+calibration#Sensorcalibration-Thermalcalibration

nuggetz

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #95 on: May 06, 2016, 05:23:01 pm »
Does anyone have whatever files one would need to have a proper Revo made at one of those online pcb manufacturing places? Not sure what the proper terminology is. I love this platform and it's a shame that there are no quality boards available. I may just go the Pixhawk route if this isn't possible.


Sent from my iPhone using Tapatalk


MGR17

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #97 on: May 06, 2016, 06:13:49 pm »
Apologies I mis-typed it should have read C9. My barometer does not seem to register changes in altitude/pressure, has anyone else experienced/overcome this problem?

hwh

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #98 on: May 06, 2016, 10:26:06 pm »
...My question therefore is removing D9 likely to help or is that just to reduce fluctuations.
I have also been trying the GPS functions with little success and wondered if  they need a working barometer to function....

Removing C9 just fixes the problem of the barometer varying too much, it wouldn't do any good for the barometer not working at all.

Your description of "with little success" doesn't really give enough info on what problem you're having to suggest anything.  A little detail on what it's doing or not doing would help.

MGR17

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #99 on: May 07, 2016, 03:13:44 pm »
When placed in position hold  or RTH the quad just fly's off and I have to revert to non GPS mode. I there fore wondered if having s unchangingly barometer could be the cause.  The only other possibly unusual thing I am doing is that I set my home locatation at my house calibrate everything but then go 3 miles to my flying field. I have also tried checking the home location not set  box before proceeding to the flying field. Both approaches result in attempted flyaways

Mateusz

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #100 on: May 07, 2016, 09:30:06 pm »
Both approaches result in attempted flyaways

Is your external magnetometer (AuxMag) calibrated and always green ? Does model react up/down/right/left correct in GCS model view ? Is model stable when in reset or when motors are running but not yet in the air ? Might be magnetic interference to magnetometer or bad mag calibration. No oscillations in EKF (Atitude states with INS31) ?

Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #101 on: May 07, 2016, 09:48:24 pm »
Quad will not arm in EKF unless Home is set.

Also Home and Base are two different things used for different purposes.

Home is used for GPS coordinates.  When using EKF, the coordinates are relative to Home.

Base is just where it returns to when you do RTB.  The default for Base is that it is set each time you arm a new battery (once GPS gets a good fix).

Home should be set "close to where you fly" but doesn't generally hurt anything if not.  Example:  If my Home is set to flying field (50km away) and I fly EKF at my house (50km away from where Home is set), my coordinates on the GCS map are off by several hundred meters, but it is all relative so it just doesn't matter.

It doesn't fly away if Home is a long way away, it just means that it thinks it is here when it is there.  For me it was 300m wrong when Home was 50k away.  It really only hurts if you are using waypoint flight, like trying to fly between trees on the map.  The map will be wrong (by e.g. 300m) and thus the trees will be hard to avoid.

PH flyaway (really this exact thing happens in any GPS mode) would usually be caused by bad mags or by GPS failure after takeoff.  One time it happened to me and I had a log, I researched it and found that the mags were bad at high power in the air.  Another time it happened to me because I couldn't get it to arm with my FPV switched on, so I switched FPV off, armed, then switched FPV back on, then flew (with a GPS signal that had gone bad).  I learned... :)

Your high current (motor) wiring MUST be twisted correctly and it is a good idea to test the mags at high motor power.  Make a log in a high power test flight that does not use EKF or GPS and make sure the mags stay green no matter what direction you fly.  Better yet, strap it down to your back porch, and watch the mag scope while you run the motors up to high power.  It should change very little (like 10% or less at full power).  This must be done with props on so there is a lot of current flow.  Be careful.

One way that might make it easier to "hold down" is to swap props so it pushes down instead of trying to lift off.  Take all props off and put them on (upside down if you like) the motor to the immediate CW (or CCW).

I wrote this quickly.  I hope it helps.

MGR17

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #102 on: May 08, 2016, 08:54:46 am »
Many thanks for all your suggestions,  Just one point I am using  the internal magnetometer but have placed the Revo on the top plate of a qav250 away from the hhigh current wiring.  I had tried high throttle and the mag traces looked stable but I will try that again. 

Mateusz

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #103 on: May 08, 2016, 09:24:53 am »
Many thanks for all your suggestions,  Just one point I am using  the internal magnetometer but have placed the Revo on the top plate of a qav250 away from the hhigh current wiring.  I had tried high throttle and the mag traces looked stable but I will try that again.

Are your power wires twisted ? Top plate of 250mm quad might not work, you need AuxMag and ~14-16cm mast for GPS navigation to work. Also it seems you already know at least one of your sensors is not working, and other gives noise. Why ignoring that is not so good idea I replied here https://forum.librepilot.org/index.php?topic=1512.msg11142#msg11142

To get better understanding I suggest reading this great post by Cliff https://forum.librepilot.org/index.php?topic=15.msg36#msg36
« Last Edit: May 08, 2016, 09:33:48 am by Mateusz »

MGR17

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Re: Warning: At least some sellers are selling Revos with bad baros
« Reply #104 on: May 08, 2016, 11:40:38 pm »
I think just need to get my barometer working as it fly's well in stabilised mode .  One thing I have noticed is that when I upgraded the firmware from open pilot to librepilot there was a yellow warning exclamation mark in the area to the right of the check some etc. Is this normal ?

In the meantime I will have to continue using my multiwii quad where  all the  GPS functions are working well with the internal magnetometer