Author Topic: DIY ultrasonic anemometer?  (Read 2760 times)

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Offline vreihen

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DIY ultrasonic anemometer?
« on: April 02, 2016, 07:15:58 PM »
There are a few web articles from people who have built their own, but I have never really seen them discussed here.  Because of my love/hate relationship with my Acu-Rite 5-in-1 and not being able to mount it high enough to get clean wind readings, I was thinking about either buying or building an ultrasonic anemometer that wouldn't be as heavy/off-balance on a tall mast.

I saw the Netatmo sensor is now available, and the price is certainly attractive.  They also have a web-based API for polling your own station data, but I'm not going down that road again after seeing both my Acuu-Rite MBW and Wink home automation system have issues when unexpected server outages struck.  I don't know how it talks back to their base station, or if rtl_433 could ever capture/debug the packets (which it doesn't as of today).  I also don't know what its sample rate is, and would not settle for anything less than 15 seconds/packet.

Anyway, I was just curious if anyone has done any tinkering along these lines?????
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Offline vreihen

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Re: DIY ultrasonic anemometer?
« Reply #1 on: April 03, 2016, 06:52:48 PM »
http://weewx.com/hwcmp.html

To answer my own question about the possibility of hijacking the Netatmo sensor, the above web site claims that their sensors only update at 5-minute intervals.  Fine for a consumer smartphone app, but far from frequent enough for use as a real PWS.

Homebrew or eBay it is.....
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Offline CW2274

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Re: DIY ultrasonic anemometer?
« Reply #2 on: April 03, 2016, 07:16:52 PM »
http://weewx.com/hwcmp.html
the above web site claims that their sensors only update at 5-minute intervals.
You gotta be kidding me, the wind? An EF5 could of come and gone by then.  :lol:

Offline Bushman

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Re: DIY ultrasonic anemometer?
« Reply #3 on: April 03, 2016, 07:40:39 PM »
This seems to be the gold standard in DIY ultrasonic anemometers. https://soldernerd.com/2014/11/14/arduino-ultrasonic-anemometer-part-1-getting-started/
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Offline vreihen

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Re: DIY ultrasonic anemometer?
« Reply #4 on: April 03, 2016, 08:47:17 PM »
You gotta be kidding me, the wind? An EF5 could of come and gone by then.  :lol:

Here's another site confirming 5-minute update intervals:

http://www.weathershack.com/product/netatmo-urban-weather-station.html

Fine for use as an "urban weather station" (their words), but not so useful as an instrument (unless cluttering up WU with badly-sited PWS data counts as useful).  :lol:

This seems to be the gold standard in DIY ultrasonic anemometers. https://soldernerd.com/2014/11/14/arduino-ultrasonic-anemometer-part-1-getting-started/

For the sake of documentation completeness, the first attempt that I found was from 2010, and I believe was cited as the above's source of info/inspiration:

http://hackaday.com/2013/08/21/ultrasonic-anemometer-for-an-absurdly-accurate-weather-station/

He has published a complete source .ZIP package, which includes a .PDF file with lots of math, sample code, and schematics:

https://storage.googleapis.com/google-code-archive-downloads/v2/code.google.com/mysudoku/UltrasonicAnemometer.zip

It seems like all of the info to make a second generation DIY sensor that's easier to reproduce is out there, but someone just needs to look at it in terms of making it easy for those without the desire to breadboard circuits to build.  I'm thinking a laser-cut plywood/aluminum/lexan disc with mounting holes for the sensors placed accurately, a piggyback board for a common Arduino processor board or even the Raspberry Pi, and other things that could simplify the construction and bring the finished product down to a manageable build with basic tools.....
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