This is all my code
#define uint unsigned int
#define ulong unsigned long
#define PIN_ANEMOMETER 3 // Digital 2
#define PIN_VANE 5 // Analog 5
// How often we want to calculate wind speed or direction
#define MSECS_CALC_WIND_SPEED 5000
#define MSECS_CALC_WIND_DIR 5000
volatile int numRevsAnemometer = 0; // Incremented in the interrupt
ulong nextCalcSpeed; // When we next calc the wind speed
ulong nextCalcDir; // When we next calc the direction
ulong time; // Millis() at each start of loop().
// ADC readings:
#define NUMDIRS 8
ulong adc[NUMDIRS] = {26, 45, 77, 118, 161, 196, 220, 256};
// These directions match 1-for-1 with the values in adc, but
// will have to be adjusted as noted above. Modify 'dirOffset'
// to which direction is 'away' (it's West here).
char *strVals[NUMDIRS] = {"W","NW","N","SW","NE","S","SE","E"};
byte dirOffset=0;
//=======================================================
// Initialize
//=======================================================
void setup() {
Serial.begin(9600);
pinMode(PIN_ANEMOMETER, INPUT);
digitalWrite(PIN_ANEMOMETER, HIGH);
attachInterrupt(0, countAnemometer, FALLING);
nextCalcSpeed = millis() + MSECS_CALC_WIND_SPEED;
}
//=======================================================
// Main loop.
//=======================================================
void loop() {
time = millis();
if (time >= nextCalcSpeed) {
calcWindSpeed();
nextCalcSpeed = time + MSECS_CALC_WIND_SPEED;
}
if (time >= nextCalcDir) {
calcWindDir();
nextCalcDir = time + MSECS_CALC_WIND_DIR;
}
}
//=======================================================
// Interrupt handler for anemometer. Called each time the reed
// switch triggers (one revolution).
//=======================================================
void countAnemometer() {
numRevsAnemometer++;
}
//=======================================================
// Find vane direction.
//=======================================================
void calcWindDir() {
int val;
byte x, reading;
val = analogRead(PIN_VANE);
val >>=2; // Shift to 255 range
reading = val;
// Look the reading up in directions table. Find the first value
// that's >= to what we got.
for (x=0; x<NUMDIRS; x++) {
if (adc[x] >= reading)
break;
}
//Serial.println(reading, DEC);
x = (x + dirOffset) % 8; // Adjust for orientation
Serial.print(" Dir: ");
Serial.println(strVals[x]);
}
//=======================================================
// Calculate the wind speed, and display it (or log it, whatever).
// 1 rev/sec = 1.492 mph
//=======================================================
void calcWindSpeed() {
int x, iSpeed;
// This will produce mph * 10
// (didn't calc right when done as one statement)
long speed = 2.4;
speed *= numRevsAnemometer;
speed /= MSECS_CALC_WIND_SPEED;
iSpeed = speed; // Need this for formatting below
Serial.print("Wind speed: ");
x = iSpeed / 10;
Serial.print(x);
Serial.print('.');
x = iSpeed % 10;
Serial.print(x);
numRevsAnemometer = 0; // Reset counter
}
