wind.py

from gpiozero import Button
import time
import math
import statistics

wind_count = 0  # Counts how many half-rotations
radius_cm = 9.0  # Radius of your anemometer
wind_interval = 5  # How often (secs) to report speed

ANEMOMETER_FACTOR = 1.18

store_speeds = []


# Every half-rotation, add 1 to count
def spin():
    global wind_count
    wind_count = wind_count + 1
    # print("spin" + str(wind_count))


def reset_wind():
    global wind_count
    wind_count = 0


# Calculate the wind speed
def calculate_speed(time_sec):
    global wind_count
    circumference_cm = (2 * math.pi) * radius_cm
    rotations = wind_count / 2.0

    dist_km = (circumference_cm * rotations) / 100000

    km_per_sec = dist_km / time_sec
    km_per_hour = km_per_sec * 3600

    return km_per_hour * ANEMOMETER_FACTOR


wind_speed_sensor = Button(5)
wind_speed_sensor.when_pressed = spin

# Loop to measure wind speed and report at 5-second intervals
while True:
    start_time = time.time()
    while time.time() - start_time <= wind_interval:
        reset_wind()
        time.sleep(wind_interval)
        final_speed = calculate_speed(wind_interval)
        store_speeds.append(final_speed)

    wind_gust = max(store_speeds)
    wind_speed = statistics.mean(store_speeds)
    print(wind_speed, wind_gust)