windmill.rb

# For local Docker vendor dependencies
require_relative 'bundle/bundler/setup'

require "iron_mq"
require "iron_worker"
require "yaml"
require "json"
require "forecast_io"

# Set some constants
DENSITY  = 1.23 # Air density
BETZ     = 0.59 # Max power output
PI       = 3.14 # PI
DIAMETER = 50   # Windmill blade size

# Area is needed to calculate power
def calc_swept_area(blade)
	return PI * ((blade / 2) * (blade / 2))
end

# Calculate power generation
def calc_power(area, speed)
	return BETZ * area * DENSITY * (speed * speed * speed)
end

# Load config and payload
cfg = YAML.load_file('windmill.config.yml')
lat = IronWorker.payload['lat']
lon = IronWorker.payload['lon']

# Fire up a fake windmill
puts "Windmill started at location: #{lat} #{lon}\n"

# Hit Forecast API with coordinates
ForecastIO.api_key = "#{cfg['forecast']['key']}"
forecast = ForecastIO.forecast(lat, lon)

# Current weather conditions
humidity = forecast.currently.humidity
temp     = forecast.currently.temperature
pressure = forecast.currently.pressure
speed    = forecast.currently.windSpeed
bearing  = forecast.currently.windBearing

puts "Temperature: #{temp} Fahrenheit\n"
puts "Humidity: #{humidity}\n"
puts "Pressure: #{pressure} Millibars\n"
puts "Wind Speed: #{speed} mph\n"
puts "Wind Bearing: #{bearing} degrees\n"

# Run energy calculations
area  = calc_swept_area(DIAMETER)
power = calc_power(area, speed) 

puts "Windmill current power generation: #{power} Watts\n"

# Format data and place in queue
ironmq = IronMQ::Client.new
queue = ironmq.queue("windmill_calc")
hash = { 
 	     :lat => lat, 
 	     :lon => lon, 
 	     :humidity => humidity, 
 	     :temp => temp, 
 	     :pressure => pressure, 
 	     :speed => speed, 
 	     :bearing => bearing, 
 	     :power => power 
       }
queue.post(JSON.generate(hash))

puts "Posted data to queue\n"