mqtt_sensor_pub.rb

#!/usr/bin/ruby
#  -*- encoding: utf-8 -*-
#
# mqtt_sensor_pub.rb - Sample script to publish the sensor data using the MQTT
#
#   $ sudo gem install serialport
#   $ sudo gem install mqtt
#
require 'rubygems'
require 'serialport'
require 'mqtt'
require 'JSON'

dev = "/dev/cu.usbmodem1d1131"

conn_opts = {
    remote_host: "mqtt.example.com",
    remote_port: 1883,
    username:    "username",
    password:    "password",
}

sp = SerialPort.new(dev, 9600)

loop do
    begin
        MQTT::Client.connect(conn_opts) do |c|
            while true do
                l = sp.gets
                puts l

                begin
                    json = JSON.parse(l)
                    topic = json["name"]
                    json.delete("name")

                    json_str = JSON.generate(json)
                    puts "publish : " + json_str
                    c.publish(topic, json_str)

                rescue Exception => e
                    puts e
                end
            end
        end

    rescue Exception => e
        puts e
    end
    sleep 5
end