1 - serial I / O
2 - VDD
3 - Regulator CE (Chip Enable)
4 - GND
There will be pulses from line 1, probably a square wave. You could use an interrupt routind to count these pulses. See -
http://arduino.cc/en/Reference/AttachInterruptThe minimal code should be like this
volatile unsigned long counter = 0;
void setup()
{
Serial.begin(115200);
attachInterrupt(0, wind, RISING); // IRQ 0 == PIN 2
}
void loop()
{
if (millis() - last > 1000) // display counter once per second
{
Serial.println(counter);
last = millis();
}
}
void wind()
{
counter++;
}