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Post by wintermute3 on Sept 19, 2019 18:31:48 GMT -8
From the docs: "One contact closure a second indicates 1.492 MPH (2.4 km/h)." I am using an Arduino with software that was working properly until I replace the WeatherRack sensors with a newly purchased unit (don't ask what happened to the old ones!). After replacing the WeatherRack my windspeed readings are 5-10 times what is expected. At first I suspected debounce issues with the reed switch, but even increasing the debounce time from 1ms to 10ms makes no difference. Is it possible that the specific unit I received is really that sensitive? I can say that by visual observation it spins like a bandit in the slightest breeze, so that seems to be a real possibility. Anyone have any insight here? FWIW I just ordered a hand-help anemometer so I can do an A/B comparison, and I may solve the problem by adjusting the scale factor in the software by fiat, but it is still a bit mysterious.  Some data from today - I promise we did not have a hurricane! |
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Post by SDL on Sept 23, 2019 12:09:40 GMT -8
Hmm.
And a new problem we have never seen before!
Seems to me it couldn't be off by 10X. I could see a 2X (double relays) but 10X? It's got to be noise. Is it possible you have the units mixed up.
BP
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Post by wintermute3 on Sept 27, 2019 11:28:58 GMT -8
I finally took the anemometer off the pole and put it on my workbench, and verified that I get 2 pulses per revolution. Is this normal? If not, is it something I could (or should) fix by disassembling the unit (carefully)?
I am going to go triple-check the software again, although all appears legit on the surface, and it was working with the old anemometer. I'll post here what I finally determine!
Also, I do now have a handheld anemometer so I can get a reference for comparison.
- Michael
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Post by SDL on Sept 28, 2019 14:18:17 GMT -8
Hmm. How odd. Do your measurements and let's get to the bottom of this. This is really odd. I would not disassemble it. Would you measure the cup size and the span of the anemometer? I want to make sure you don't have some odd one. Picture too!
BP
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Post by wintermute3 on Oct 6, 2019 19:02:32 GMT -8
I have corrected a software issue that was causing a second 2x error on top of the 2x pulses per revolution issue, so the actual total error was 4x. With the software now expecting 2 pulses/revolution and the scaling error corrected, I now track correct wind speed in agreement with the handheld anemometer.
Is the 2x pulse thing a known issue for some units?
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Post by SDL on Oct 7, 2019 10:26:25 GMT -8
Please publish the software changes you made on here. This is a new one on us. I'd like to run a test on my bench unit.
BP
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nedhead
New Member
Retired EE
Posts: 15
Raspberry Pi: Yes
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Post by nedhead on Apr 24, 2020 13:20:37 GMT -8
I'm having a similar problem with my anemometer. Where does one find these settings in the software ?? I did find the settings in the WeatherRack subdirectory.  I also changed the number of pulses to 2. Still need a handheld to verify readings - which isn't your problem. |
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Post by SDL on Apr 25, 2020 12:14:04 GMT -8
Waiting for more information on this problem.
BP
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nedhead
New Member
Retired EE
Posts: 15
Raspberry Pi: Yes
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Post by nedhead on May 19, 2020 8:13:51 GMT -8
I solved the speed problem with the same change to pulses per revolution (2). Now I see a few random very high (70-120mph) gust speeds while the average gusts are running 5-35 mph. Advice ? Attachments:
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Post by SDL on May 19, 2020 15:02:55 GMT -8
Ned,
What are you running the WeatherRack on? What computer I mean?
I suspect that we might be seeing a multitasking problem here.
BP
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nedhead
New Member
Retired EE
Posts: 15
Raspberry Pi: Yes
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Post by nedhead on May 20, 2020 5:40:30 GMT -8
Raspberry Pi 3B
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Post by SDL on May 20, 2020 7:55:17 GMT -8
Makes sense. This needs to be re-written for the Raspberry Pi. The trouble is that you sometimes don't get the processor when you want it (preemptive multitasking) and so the values can be bad.
BP
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I also changed the number of pulses to 2. Still need a handheld to verify readings - which isn't your problem.