Set color of a Hue lightbulb based on fine-grained rain information

buien-hue.rb

#!/usr/bin/env ruby

require 'open-uri'
require 'json'
require 'hue'

delft="http://www.buienradar.nl/Json/RainForecast3Hours?lat=52.006&lon=4.355&weatherstationid=6344&streetlevel=false"

percipitation = JSON.parse(open(delft).read)['forecasts'][1]["precipation"]

sat = if percipitation < 2
        0
      elsif percipitation > 2 and percipitation <= 10
        percipitation * 10 + 50
      else
        220
      end

client = Hue::Client.new
living_room = client.lights.find{|l| l.name == "Living room"}

if living_room.on?
  living_room.set_state({:saturation => sat, :hue => 46920 }, 20)
end

This will set the colour of the living room lightbulb to a shade of blue based on fine grained shower ('bui') information available at 5-min resolution from buienradar.nl. To extract the url for your city, go to buienradar.nl, search for your city and watch the browser do Ajax calls to URLs that look like the one for Delft. Saturation values are currently random, as no shower is forecasted for the next 3-4 days :-)