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Author Topic: How do you cover / tune your barometer?  (Read 2712 times)

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Offline teslahed

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How do you cover / tune your barometer?
« on: August 09, 2012, 15:07:29 »
I'm not getting as good performance from my barometer as i would like. I have covered it from prop wash by sticking a little square of double sided sticky foam tape on the chip itself but now I'm wondering if that's the best way to do it.

What do other people use and do you tune your altitude hold PIDs much or do you find the defaults work fine?

It's the MS5611 high precision barometer in the GY86 10DoF sensor board i have.


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Offline Gaza07

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Re: How do you cover / tune your barometer?
« Reply #1 on: August 09, 2012, 15:20:00 »
I normally squash a bit of open cell foam onto it, which is easy when you have a separate mcu and sensor board so it just get sandwiched between the 2, you not supposed to cover the holes with anything that can breathe, the altitude hold from the ms5611 should be a lot better than the bmp085 but the sonar is the most accurate but only at low altitude,
If this is multi wii I have in the past found the default values to be about as good as it gets but that was using a bmp085, I have never used a ms5611 with multi wii to date, If you are going to tweak things be carefull with the velocity setting as I altered it once and my copter shot of towards the moon very quickly, just make small adjustments each time and only alter one setting at a time, although default is probably going to end up the best setting  ::)

Offline Toledodave

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Re: How do you cover / tune your barometer?
« Reply #2 on: December 23, 2013, 21:53:48 »
I used the foam my motors came in seems perfect for this application.

Offline Biffa

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Re: How do you cover / tune your barometer?
« Reply #3 on: December 23, 2013, 22:23:11 »
I have a bunch of sanding blocks. Cut off the emery paper an underneath is an open cell foam. Certainly worked on my Crius build ~~
Steve

Offline nub

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Re: How do you cover / tune your barometer?
« Reply #4 on: December 23, 2013, 22:44:45 »
i used a bit of dark spongy foam with some insulating tape, it done the job quite well.

canny mind what PID settings i ended up with but do remember having to mess about with them quite a bit to get to hold its height in FF, that was with a BMP085.
Same old, different place.

Offline Hands0n

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Re: How do you cover / tune your barometer?
« Reply #5 on: December 23, 2013, 23:04:03 »
Whatever you cover it with has to be able to breathe.  I use the foam packing that disk drives arrive in. It is dark grey, totally impervious to light and is open cell, that is it breathes. 

One of the neatest methods I saw was someone cut the top off a car tyre valve cap and glued it to the FC such that it encompassed the barometer chip, and then packed light-opaque open foam into the opening, making a completely light-tight and breathable enclosure for the Baro.

On my APM 2.5 I have a slab of that grey foam that runs along most of the length of the FC inside its 3DR case.
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Danny
"Its better than bad, its good"

Current FCs: APM 2.5, Naze32, CC3D, KK2.1.5
Aircraft: TBS Disco, 450 Firefly, 250 Pro, ZMR250, Hammer 250, Hubsan X4, Bixler 2

Offline GdLookinMingeR

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Re: How do you cover / tune your barometer?
« Reply #6 on: December 23, 2013, 23:39:58 »
I have some open cell black foam
if you would like some posted send me an addy
i will post you a 50x50 F.O.C.
Merry Chrimbo
Naza lite on Modified x525 frame, tarot 2d gimbal and some dodgy legs made from hk landing gear fpv
CPO135 Tricopter, Naze32 full, GPS, Cleanflight, Mobius, FPV
Tek Sumo, that i have never got off the ground
and Various other Fails...   :-)

Offline barneyg

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Re: How do you cover / tune your barometer?
« Reply #7 on: December 24, 2013, 07:36:03 »
After running some bench tests I've removed the foam from my ms5611 completely, I was just getting the PID's dialed in before the weather closed in here ... At least with multiwii the ms561q is affected by temp quite a lot and if you are also using a 3dr telemetry module or Bluetooth especially the serial IO causes ms5611 to warm significantly (on my crius it is quite close to the UART stuff) ... Over the course of about 15 minutes my quad can drop to -15m (while sitting on the bench) if I cover the chip ... And it settles on about -1m if I don't ... In actual flight the propwash has not been a problem, not sure about light effects - my fc is between the top and bottom plates of a 450 clone.