Wind measurements with Davis anemometer

wind.py

import time
from gpiozero import Button
from signal import pause
import statistics
import pyrebase
import Adafruit_DHT as dht
#The "black" wire (wind speed) of Davis connected to PIN29 as GPIO05
#the "red" wire (ground) of Davis is connected to PIN39 ground
#the "green" wire (wind direction) of davis is connected to PIN31 as GPIO06
#the "yellow" wire is connected to 5V PIN02

DHT_PIN = 4 #for humidity and temperature

db_url = 'https://home-iot-wind.firebaseio.com/' 
config = {
  "apiKey": "*****************",
  "authDomain": "home-iot-wind.firebaseapp.com",
  "databaseURL": db_url,
  "storageBucket": "home-iot-wind.appspot.com"
}
firebase = pyrebase.initialize_app(config)
db = firebase.database()

wind_speed_sensor = Button(5)
wind_count = 0

interval = 3

def spin():
    global wind_count
    wind_count = wind_count + 1
    #print("spin" + str(wind_count))

#time shall be in seconds
def calc_speed(spins, interval):
    #based on Davis tech document
    # V = P*(2.25/T) the speed is in MPh
    # P = no. of pulses per sample period
    # T = sample period in seconds
    wind_speed_mph = spins * (2.25 / interval) 
    return wind_speed_mph

def reset_wind():
    global wind_count
    wind_count = 0

store_speeds = []

wind_speed_sensor.when_pressed = spin

while True:
    start_time = time.time()
    print('##### 10-min started #####')
    while time.time() - start_time <= 600:    
        print('Start 3 second')
        humidity, temperature = dht.read_retry(dht.AM2302, DHT_PIN)
        if humidity is not None and temperature is not None:
            print("Temp={0:0.1f}*C  Humidity={1:0.1f}%".format(temperature, humidity))
        count_start = wind_count
        time.sleep(3)
        count_end = wind_count
        spins = count_end - count_start
        bws_3_sec = calc_speed(spins, 3)
        data_3sec = {
            "bws-3-sec": bws_3_sec,
            "temperature": temperature,
            "humidity": humidity,
            "timestamp": time.time()
            }
        #build some path
        db.child("home").child("wind").child("3_sec").push(data_3sec)
        print('Number of spins: ', spins)
        print('Wind speed (mph): ', bws_3_sec)
        print('Global count: ', wind_count)
        #reset_wind()
    #Measure for 10-min
    bws_10_min = calc_speed(wind_count, 600)
    data_10_min = {
        "bws_10_min": bws_10_min,
        "temperature": temperature*2,
        "humidity": humidity,
        "timestamp": time.time()
        }
    db.child("home").child("wind").child("10_min").push(data_10_min)
    print('###### 10-min data #####')
    print('Global count: ', wind_count)
    print('10-min BWS: ', bws_10_min)
    print('##### 10-min END #####')
    reset_wind()


""" while True:
    start_time = time.time()
    while time.time() - start_time <= interval:
        reset_wind()
        time.sleep(interval)
        final_speed = calc_speed(interval)
        store_speeds.append(final_speed)

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

pause()

# Hello from Mender update :)