I got my hands on a second hand weather station (no controller, just the parts) which I am trying to get working with the Arduino. The anemometer is my first port of call. Opening it up revealed far more than I was expecting.
The item of interest is the anemometer sensor. One of the blades in the little "fan" is magnetic. The pickup though is sealed in the plastic case which I cannot get to. It simply has two wires hanging from it. Sticking a voltmeter to it and bringing a strong magnetic past it gives me a voltage of up to 7mv. Connecting this to the Arduino though picks up so much noise and not enough of a change to make a valid measurement.
I simply have one end of the "thing" into ground, the other into analogin. I have tried pulling it up with a 47k resistor but the same happens.
How can I accurately read these tiny pulses? I cannot average them as this thing spins pretty quickly.
Alternatively, anyone know what the sensor might be? It's tiny (like a small cap). It has a resistance of 328 ohms.