When the wind is calm any direction is meaningless, continuing to report the last wind direction is even more meaningless. For previous conditions then use the pastcast conditions based back in time or averaged progressively back over time should be in the reporting loop.
With a good system that is level and has good bearings, it is possible for the vane to move without there being enough wind for the cups to move enough to compute a wind speed.
Also disagree. If you have a vane that moves before the cups in, then you have a vane that flops around like a fresh fish on the deck or you have cups that engage waaaay too slowly.
No problem with you disagreeing with what I didn't say.
What ever that means.
What it means is that I spoke about the cups moving enough to make a measurement. Mattk responded about the van moving before the cups or the cups engaging "waaay to slowly". Why is that different to what I was saying?
The normal microswitch anemometer in many home weather stations must do over 1 to 2 revs to get to get at least 2 pulses to measure instantaneous wind speed, but what normally happens is that the measurement device waits a fair bit longer to estimate the wind speed by counting pulses over a time period. A few use both methods, I believe. Often the weather station then only reports the wind speed every 10 to 60 seconds.
So, when I was talking about a wind vane moving before a wind calculation can be done, it is in the context of what comes out of the weather station because that is what is the reading we see. It is not about whether the cups spins a bit when the vane moves and stops.
Hopefully that explains my comment