weatherstation/firmware/sensor_wind.ino

#include "config_user.h"
#include "config.h"

unsigned int anemometerRotations = 0;

ICACHE_RAM_ATTR void _anemometerInterrupt()
{
  anemometerRotations++;
#ifdef DEBUG
  Serial.print("*");
#endif
}

float wind_speed()
{
  anemometerRotations = 0;

  int interruptNumber = digitalPinToInterrupt(ANEMOMETER_PIN);

  attachInterrupt(interruptNumber, _anemometerInterrupt, RISING);
  delay(1000 * WIND_SENSOR_MEAS_TIME_S); // time to measure
  detachInterrupt(interruptNumber);

  // calculate the speed as km/h
  float tmp_speed = (float)anemometerRotations * WINDSPEED_FACTOR;

#ifdef DEBUG
  Serial.print("Windspeed: " + String(tmp_speed));
#endif

  return tmp_speed;

}