Was monitoring the AAG 1w “current voltage” in the 1w setup screen vs humidity.
At first, I expected it to vary linearly with humidity. Not so.
Here are some data points
Humidity Voltage
96% 4.30 v
100 4.24
80 3.77
65 4.23
50 4.31
This was puzzling. The WD plotted humidity seems reasonable and varies as one would expect during the day. Some time back while bench testing, it agreed reasonably well with the “wall clock” type humidity values.
What is the voltage that is displayed by WD?
Is it V at the a/d converter input? If so, one can use the math in
http//www.ibutton.com/weather/humsensor.pdf
to back out the VDD value.
If one does this, it appears that the Vdd value (the humidity sensor voltage derived from parasite power) varies from a bit less than 6 volts at high humidity to over 12 volts at <50% humidity. This is an RS-232 port setup. I suppose it could be as high as about 14 volts or so.
It appears that the humidity sensor loads down the parasite power source significantly at high humidity levels.
Can VDD also be edited?
The presently edited value is more confounding than enlightening.