$ git clone https://github.com/takasehideki/fukuokaex11

$ cd home_weather_phx/

window.onload = function () {
  var csvData = csvToArray("dhtdata.csv");
  var today = "2018-12-04 ";
  ...
};

$ MIX_ENV=dev mix phx.server

defmodule HomeWeatherPhx.Mixfile do
  use Mix.Project

  def project do
    [
      app: :home_weather_phx,
      version: "0.0.1",
      elixir: "~> 1.4",
      elixirc_paths: elixirc_paths(Mix.env),
      compilers: [:phoenix, :gettext] ++ Mix.compilers,
      build_embedded: Mix.env() == :prod,
      start_permanent: Mix.env == :prod,
      deps: deps()
    ]
  end

  # Configuration for the OTP application.
  #
  # Type `mix help compile.app` for more information.
  def application do
    [
      mod: {HomeWeatherPhx.Application, []},
      extra_applications: [:logger, :runtime_tools, :timex]
    ]
  end

  # Specifies which paths to compile per environment.
  defp elixirc_paths(:test), do: ["lib", "test/support"]
  defp elixirc_paths(_),     do: ["lib"]

  # Specifies your project dependencies.
  #
  # Type `mix help deps` for examples and options.
  defp deps do
    [
      {:phoenix, "~> 1.3.2"},
      {:phoenix_pubsub, "~> 1.0"},
      {:phoenix_html, "~> 2.10"},
      {:phoenix_live_reload, "~> 1.0", only: :dev},
      {:gettext, "~> 0.11"},
      {:cowboy, "~> 1.0"},
      {:timex, "~> 3.1"},
      {:grovepi, github: "adkron/grovepi", branch: "master"}
    ]
  end
end

# Watch static and templates for browser reloading.
config :home_weather_phx, HomeWeatherPhxWeb.Endpoint,
  live_reload: [
    patterns: [
      ~r{priv/static/.*(js|css|png|jpeg|jpg|gif|svg|csv)$},
      ~r{priv/gettext/.*(po)$},
      ~r{lib/home_weather_phx_web/views/.*(ex)$},
      ~r{lib/home_weather_phx_web/templates/.*(eex)$}
    ]
  ]

      {:grovepi, github: "adkron/grovepi", branch: "master"}

defmodule HomeWeatherPhx do
  @moduledoc false
  use GenServer
  use Timex
  require Logger

  defstruct [:dht]

  alias GrovePi.{RGBLCD, DHT}

  @us_pin 4 # Use port 4 for Ultrasonic

  def start_link(pin) do
    GenServer.start_link(__MODULE__, pin)
  end

  def init(dht_pin) do
    state = %HomeWeatherPhx{dht: dht_pin}

    {:ok, _pid} = GrovePi.Ultrasonic.start_link(@us_pin)

    RGBLCD.initialize()
    RGBLCD.set_text("Ready!")

    # Create CSV file
    File.write "priv/static/dhtdata.csv", ""

    DHT.subscribe(dht_pin, :changed)
    {:ok, state}
  end

  def handle_info({_pin, :changed, %{temp: temp, humidity: humidity}}, state) do
    # Measure distance
    distance = GrovePi.Ultrasonic.read_distance(@us_pin)
    distance = if distance >= 200, do: 0, else: distance

    # Get date
    date = Timex.now("Asia/Tokyo")
      |> Timex.format!( "%Y-%m-%d %H:%M:%S", :strftime )

    temp = format_temp(temp)
    humidity = format_humidity(humidity)
    distance = format_distance(distance)

    # Write data to CSV
    File.write "priv/static/dhtdata.csv", "#{date},#{temp},#{humidity},#{distance}\n", [:append]

    flash_rgb()

    RGBLCD.set_text(temp)
    RGBLCD.set_cursor(1, 0)
    RGBLCD.write_text(humidity)
    Logger.info temp <> " " <> humidity <> "" <> distance

    {:noreply, state}
  end

  def handle_info(_message, state) do
    {:noreply, state}
  end

  defp flash_rgb() do
    RGBLCD.set_rgb(255, 0, 0)
    Process.sleep(1000)
    RGBLCD.set_color_white()
  end

  defp format_temp(temp) do
    "Temp: #{Float.to_string(temp)} C"
  end

  defp format_humidity(humidity) do
    "Humidity: #{Float.to_string(humidity)}%"
  end

  defp format_distance(distance) do
    "distance: #{distance}cm"
  end
end

defmodule HomeWeatherPhx.Application do
  use Application

  # RGB LCD Screen should use the IC2-1 port
  @dht_pin 7 # Use port 7 for the DHT
  @dht_poll_interval 10_000 # poll every 10 second

  # See https://hexdocs.pm/elixir/Application.html
  # for more information on OTP Applications
  def start(_type, _args) do
    import Supervisor.Spec, warn: false

    # Define workers and child supervisors to be supervised
    children = [
      # Start the endpoint when the application starts
      supervisor(HomeWeatherPhxWeb.Endpoint, []),
      # Start your own worker by calling: HomeWeatherPhx.Worker.start_link(arg1, arg2, arg3)
      # worker(HomeWeatherPhx.Worker, [arg1, arg2, arg3]),

      # Start the GrovePi sensor we want
      worker(GrovePi.DHT, [@dht_pin, [poll_interval: @dht_poll_interval]]),

      # Start the main app
      worker(HomeWeatherPhx, [@dht_pin]),
    ]

    # See https://hexdocs.pm/elixir/Supervisor.html
    # for other strategies and supported options
    opts = [strategy: :one_for_one, name: HomeWeatherPhx.Supervisor]
    Supervisor.start_link(children, opts)
  end

  # Tell Phoenix to update the endpoint configuration
  # whenever the application is updated.
  def config_change(changed, _new, removed) do
    HomeWeatherPhxWeb.Endpoint.config_change(changed, removed)
    :ok
  end
end