A while back I looked at the datasheet for one of the automotive type rain sensors. It was a scaled down version of the traces on PCB sort of thing.
Guessing here:
The sensor can sense a single drop of rain. At speed the air moving through the sensor dries each drop. Each drop would show up as a pulse. From this you could determine how hard it was raining. Maybe good enough to set the wiper speed.
Guessing here:
The sensor can sense a single drop of rain. At speed the air moving through the sensor dries each drop. Each drop would show up as a pulse. From this you could determine how hard it was raining. Maybe good enough to set the wiper speed.