lametric_nightscout.rb

  URL = '<nightscout url>/api/v1/entries.json'.freeze

  def index
    response = JSON.parse(HTTParty.get(URL).body)
    chart_data = response.map {|r| r["glucose"].to_i}
    payload = {
      "frames": [
        {
          "text": response[0]['glucose'].to_s,
          "icon": 'i20045', # Blue circle logo
          "index": 0 # Latest glucose reading
        },
        {
          "index": 1, # Sparkline
          "chartData": chart_data.reverse
        }
      ]
    }
    render json: payload
  end