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!
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.
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!
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?