grovepi/Projects/rain_notifier/rain_notifier.py

# rain_notifier.py

'''
## License

The MIT License (MIT)

GrovePi for the Raspberry Pi: an open source platform for connecting Grove Sensors to the Raspberry Pi.
Copyright (C) 2017  Dexter Industries

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
'''

# This is a project that uses the Grove LED attached to an umbrella to remind
# people to take their umbrella if it's raining or going to rain that day.
#
# You will need to modify the first few lines for this project work for you.
# Fee free to modify the rest of the program to make it
# behave the way you want it to.
#
# Enter your zip code (or Postal Code) on the following line
# (leave the name 'zip' as is, even if you have a postal code. )
zipcode = 'YOUR_ZIP_CODE'

# once you have gotten an API Key from Wunderground (see tutorial),
# pleave provide it here
# Wunderground API Key
api_key = 'YOUR_WUNDERGROUND_API_KEY'

# if you wish to use two LEDs, provide the port number of the second LED
# The second LED is the one that will indicate
# if there's no rain in the weather prediction
# With two LEDs, one will always be on.
# if you do not want a second LED, set this to -1
clearled = 8

############################################################################
# no modifications are required after this
# however the next few lines can be tweaked easily
############################################################################

# in case of rain, do you want the LED to blink
# to catch your attention more?
# set to True for blinking, set to False for a steady warning
BLINK = True

# this is the delay between each polling of Wunderground.
# It's set to poll once every 5 minutes
# you may prefer a faster polling.
# the Wunderground free account does set a limit
DELAY = 5*60  # in seconds

# Do you prefer to work in metric or imperial?
# set METRIC to 1 to use the metric system
# set METRIC to 0 to use imperial system
METRIC = 1

# rain threshold: what's your safety zone?
# before you need an umbrella
# if METRIC is set to 1, this will be in millimeters
# if METRIC is set to 0, this will be in inches
RAIN_THRESHOLD = 1


# Pin for the rain LED on the umbrella
rainled = 7

############################################################################
# nothing needs to be modified after this
# if you are familiar with Python, feel free to change anything to improve this
# we welcome additions and suggestions
############################################################################

import urllib2
import json
from grovepi import *
import time
import sys


def clear_led(status):
    """ change clear sky LED status """
    if clearled > -1:
        digitalWrite(clearled, status)


def assign_rain(status, blink):
    """ controls the LEDs status

    Arguments:
    status: True if it will be raining
            False if there's no rain in the forecast
    blink:  True if the rain led should blink when on
            False if the rain led does not need blinking
    no return value
    """

    if status is True:  # there will be rain
        clear_led(0)    # Turn off the CLEAR LED on the umbrella

        # Light the RAIN LED on the umbrella
        # first check if it needs to be blinking
        if blink is True:
            led_blink(DELAY)  # no sleep required here
        else:
            digitalWrite(rainled, 1)
            time.sleep(DELAY)

    else:  # no rain in forecast
        # turn off the RAIN LED on the umbrella
        digitalWrite(rainled, 0)
        # Turn on the CLEAR LED on the umbrella
        clear_led(1)
        time.sleep(DELAY)


def led_blink(blinkdelay):
    """ forces the rain LED to blink
    rain LED will blink at a rate of 0.2 secs on, and 0.2 secs off
    it will blink for a duration set by blinkdelay
    no additional sleep() is required as it's incorporated in the blinking
    """
    count = 0.0
    blinkrate = 0.4
    while count < float(blinkdelay):
        digitalWrite(rainled, 1)
        time.sleep(blinkrate)
        digitalWrite(rainled, 0)
        time.sleep(blinkrate)
        count += (2*blinkrate)


#########################################################################

# Zip code of location
url = 'http://api.wunderground.com/api/' + api_key
url = url + '/geolookup/conditions/q/' + zipcode + '.json'

pinMode(rainled, "OUTPUT")
if clearled > -1:
    pinMode(clearled, "OUTPUT")


if len(sys.argv) > 1 and sys.argv[1] == 'test':
    try:
        clear_led(1)
        led_blink(5)
        clear_led(0)
    except KeyboardInterrupt:
        digitalWrite(clearled, 0)
        digitalWrite(rainled, 0)
    quit()


try:
    while True:
        f = urllib2.urlopen(url)
        json_string = f.read()
        f.close()
        parsed_json = json.loads(json_string)
        location = parsed_json['location']['city']
        if METRIC is 0:
            precip_today = parsed_json['current_observation']['precip_today_in']
        else:
            precip_today = parsed_json['current_observation']['precip_today_metric']
        print("Current precipitation in %s is: %s" % (location, precip_today))

        if float(precip_today) > float(RAIN_THRESHOLD):
            print("Rain today, take the umbrella")
            assign_rain(True, BLINK)

        else:
            print("No Rain today")
            assign_rain(False, BLINK)

except KeyboardInterrupt:
    clear_led(0)
    digitalWrite(rainled, 0)