Grafana

Mix.install([:req, :exqlite])

defmodule Grafana do
  def loop(conn) do
    case Req.get!("http://192.168.1.10:8080/temp") do
      %{body: %{"humidity" => humidity_string, "temperature" => temperature_string}} ->
        {humidity, _} = Float.parse(humidity_string)
        {temperature, _} = Float.parse(temperature_string)

        {:ok, statement} =
          Exqlite.Sqlite3.prepare(
            conn,
            "insert into readings (humidity, temperature, time) values (?1, ?2, ?3)"
          )

        :ok = Exqlite.Sqlite3.bind(statement, [humidity, temperature, System.os_time(:second)])
        :done = Exqlite.Sqlite3.step(conn, statement)

        IO.inspect(humidity, label: "humidity")
        IO.inspect(temperature, label: "temperature")

      _ ->
        nil
    end

    Process.sleep(5000)
    Grafana.loop(conn)
  end
end

{:ok, conn} = Exqlite.Sqlite3.open("file:main.db")

:ok =
  Exqlite.Sqlite3.execute(
    conn,
    "create table if not exists readings (id integer primary key, humidity real, temperature real, time integer)"
  )

Grafana.loop(conn)

SELECT
  time,
  temperature AS "Temperature",
  humidity AS "Humidity"
FROM readings
ORDER BY time