poop latest phone location onto ssd1306 lcd

location_to_lcd.rb

!# /usr/bin/env ruby

require 'mqtt'
require 'json'
require 'yaml'
require 'bigdecimal'
require 'logger'
require 'SSD1306'
require 'rufus-scheduler'

class LocationLCD
  version = '0.0.1'

  def initialize(arguments, stdin)
    @sched = Rufus::Scheduler.new
    @client = MQTT::Client.new
    @client.host = ""
    @client.port = 8883
    @client.ssl = 'TLSv1'
    @client.ca_file = "" 
    @client.username = ""
    @client.password = ""

    @lcd = SSD1306::Display.new
    @mutex = Mutex.new

    @logger = Logger.new(STDOUT)
    #@logger = Logger.new('locationlcd.log', 10, 1048576)
    @logger.level = Logger::INFO
  end

  # Fetch a location update and set our local latitude & longitude
  def fetch_location
	  topic,message = @client.get('owntracks/#')
	  begin
		  parsed = JSON.parse(message)
		  if(parsed["_type"] == "location")
			  @mutex.synchronize {
				  @latitude = BigDecimal(parsed["lat"], 7)
				  @longitude = BigDecimal(parsed["lon"], 7)
				  if (@latitude > 0)
					  @latNS = 'N'
				  else
					  @latNS = 'S'
					  @latitude = 0 - @latitude
				  end
				  if (@longitude > 0)
					  @lonEW = 'E'
				  else
					  @lonEW = 'W'
					  @longitude = 0 - @longitude
				  end
			  }
		  end
	  rescue JSON::ParserError => e
		  # message is invalid json
	  end
  end

  def tick
    # format the message for our lcd.
    # The first two lines are yellow; all other lines are blue
    @mutex.synchronize {
	    lcdmessage = sprintf("%s\n\n%.3f %s\n%.3f %s", 
				 Time.now.strftime("%Y-%m-%d %H:%M:%S"),
				 @latitude, @latNS, @longitude, @lonEW)
	    @lcd.clear
	    @lcd.print(lcdmessage)
	    @lcd.display!
	    @logger.info(lcdmessage)
    }

  end

  def run
    @client.connect()
    fetch_location

    @sched.every '30s' do
      fetch_location
    end
    @sched.every '1s' do
      tick
    end
    @sched.join
  end

end

if __FILE__ == $0 then
  locationlcd = LocationLCD.new(ARGV, STDIN)
  locationlcd.run
end