So I have this Etherrain/8 irrigation controller (http://www.quicksmart.com/qs_etherrain.html) for which I wrote a new homeassistant component (https://github.com/hpeyerl/home-assistant/blob/dev/homeassistant/components/etherrain.py) …
I wanted to control whether things get watered depending on the likelihood of precipitation today. The darksky “Precip Probability” seems to be instantaneous, not a prediction. In this neck of the woods, environment canada actually has a fairly decent forecast that I wanted to use instead.
Enter Appdaemon. Since Environment Canada published an Atom feed of the weekly forecast, I wrote a quick python script to grab the feed and parse the POP (probability of precipitation) for a configurable number of days in advance:
import appdaemon.appapi as appapi
import feedparser
import sys
import time
import datetime
class EnvCanada(appapi.AppDaemon):
def initialize(self):
if "locator" in self.args:
loc = self.args["locator"]
else:
loc = "ab-52" # Default to Calgary
if "hr" in self.args:
hr = int(self.args["hr"])
else:
hr = 4
if "ahead" in self.args:
add=int(self.args["ahead"])
else:
add = 0
myargs={}
myargs["loc"] = loc
myargs["add"] = add
myargs["module"] = self.args["module"]
# First run immediately
h = self.run_in(self.get_pop, 1, **myargs)
# Then schedule a runtime for the specified hour.
runtime = datetime.time(hr, 0, 0)
h = self.run_once(self.get_pop, runtime, **myargs)
def get_pop(self, args):
loc = args["loc"]
add = args["add"]
d=feedparser.parse('http://weather.gc.ca/rss/city/{0}_e.xml'.format(loc))
weekdays=["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"]
today = (weekdays[time.localtime().tm_wday+add])
pop = 0
for entry in iter(d.entries):
if today in entry.title:
if "howers" in entry.title:
pop = 100
if "POP" in entry.title:
next=0
for word in iter(entry.title.split(" ")):
if next:
pop = int(word.rstrip("%"))
if word == "POP":
next=1
print("{0}: Got POP {1}".format(args["module"], pop))
self.set_state("sensor.environment_canada_pop", state = pop)
def terminate(self):
self.log("Terminating!", "INFO")
and appdaemon.yaml configuration:
EnvCanada:
module: environment_canada
class: EnvCanada
hr: 5
locator: ab-53
configuration.yaml:
binary_sensor:
- platform: threshold
name: rain_unlikely
threshold: 59
type: lower
entity_id: sensor.environment_canada_pop
- platform: mqtt
state_topic: environment_canada/pop
name: environment_canada_pop
and finally, after all that, my automations.yaml:
- id: water_front_beds_on
alias: Start Watering Front Beds mon/wed/fri at 7AM
initial_state: on
trigger:
platform: time
hours: 7
minutes: 0
seconds: 0
condition:
condition: and
conditions:
- condition: state
entity_id: binary_sensor.rain_unlikely
state: 'on'
- condition: time
weekday:
- mon
- wed
- fri
action:
service: switch.turn_on
entity_id: switch.front_beds
Comments welcome. I’m not entirely pleased with having to create a fake MQTT sensor so that appdaemon can set its state but I couldn’t see any other way to get appdaemon to create a sensor.
for the 0.51.2 garden (… yeah, 2.0 is so overated, ha versioning is kind of badass 
)