Well...that is what Trials are for I guess....and you have definitely proved that the current setup is incorrect.
Indeed.
After writing the earlier message I took a look at the debug data (every minute I have the code dump the "1 second" data records to a text file). In that the problem was very obvious with great swathes of zeros.
It looks as though clipping is cutting out anything above about 16Hz, so any rotation at above the mid 30's mph is getting lost.
The theoretical clip for the current combination (10K ohm & 220nF) is 72Hz.
10K ohm & 100nF give a theoretical clip of 15.9Hz, but I'm sure I didn't accidentally use a 100nF as the ones I have of those types look entirely different. There may of course be additional unknown factors in the circuit...
Shame that you now have to wait for decent Wx to gain access to execute a change.
In theory I could have a wire pair running all the way from the anemometer to the office as there is a length of 6 core alarm wire running alongside the UTP, though I'd need to open up the IP65 control box to swap those wires over anyway. The resulting wire run would be around 50m; even the 11m or so between the anemometer and the control box seemed to be of great concern to Eric V so the idea of 50m would probably give him nightmares!
It would seem that the old fashioned direct connection via the Inspeed serial port (to USB converter in my case), to the PC and thence WD is actually very good methodology....It certainly checks out very well with my Davis anemometer..
Yes, though, as we have worked out, that also uses a Low Pass filter. Hopefully it's just a matter of getting the values right; the great difficulty is in testing any particular set of values.
I wonder if the Weather Shop will be doing a Christmas special on VP2's this year. LOL!