sense

sensibility

use ← → keys to navigate

wheel is an extension of the foot

book is an extension of the eye

clothing is an extension of the skin

electric circuitry is an extension of the
central nervous system

IoT platform

• hosted thingspeak

  

• open sourced thingspeak

  

• 🔌 communication: sensor → rails
• ⏲ rhythm: event / periodic
• 📈 visualisation: charts + graphs
• ⚙ hooks: triggers + notification

• 🖲 event with http

• 📡 periodic with http

• 🌡 periodic with mqtt

setup

demo - http post + api

applications

IoT button

code - firmware

						

if (digitalRead(ON_PIN) == HIGH) {
  sendState(1);
} else {
  sendState(0);
}

...

void sendState(int state) {
  char path[200];
  sprintf(path, "/update?key=GQL7FLZXTK35ATAO&field1=%d", state);

  request.hostname = "10.0.1.22";
  request.port = 3000;
  request.path = path;

 http.post(request, response, headers);
}
 						
					

code - rails

						
# routes.rb
match 'update', :to => 'channels#post_data', :via => [post]

# channels_controller.rb
def post_data
  feed = Feed.new
  api_key = ApiKey.find_by_api_key(get_apikey)

  # check write permission
  # check api key
  # rate limiting
  feed.field1 = params[:field1]
  # feed.save and render
end
						
					

setup

demo - data

code - rails models

						
class Channel < ActiveRecord::Base
  ...
  belongs_to :user
  has_many :feeds
  has_many :api_keys, :dependent => :destroy
  ...
end

class Feed < ActiveRecord::Base
  ...
  belongs_to :channel
  attr_readonly :created_at
  ...
end

class ApiKey < ActiveRecord::Base
  belongs_to :channel
  belongs_to :user
  validates_uniqueness_of :api_key
end
						
					

code - rails lib

						
def generate_api_key(size = 16, type = 'channel')
  alphanumerics = ('0'..'9').to_a + ('A'..'Z').to_a
  new_key = (1..size).map {alphanumerics[Kernel.rand(36)]}.join
  ...
end
						
					

code - rails controllers

						
class FeedController < ApplicationController
  def show
    ...
    respond_to do |format|
      format.html { render :text => output }
      format.json { render :json => output,
        :callback => params[:callback] }
      format.xml { render :xml => output }
      format.csv
      format.text { render :text => output }
    end
  end
end
						
					

applications

urban waste management with ultrasonic sensors

examples

standard

setup

demo

firmware - mqtt publish

						
#include < PubSubClient.h >
#define mqtt_server "10.0.1.22"
#define topic "8DH1XFGBT2IJX6F8/field1" // topic = api_key/field

void setup() {
	...
  client.setServer(mqtt_server, 1883);
}

void loop() {
  ...
  sensorValue = analogRead(A0);
  temperature = (sensorValue / 1024.0) * 3.3 * 100.0;

  ...
  client.publish(topic, String(temperature).c_str(), true);
}
						
					

rails - mqtt subscribe

						
# bin/mqtt_sub

#!/usr/bin/env ruby
require 'mqtt'

MQTT::Client.connect('localhost', 1883) do |c|
  subscription = '8DH1XFGBT2IJX6F8/field1'

  c.get(subscription) do |topic, message|
    api_key, field = topic.split('/')

    feed = Feed.new
    # check api key and other checks
    feed[ field ] = message

    # feed.save and render
  end
end
						
					

applications

home power meter

daily
weekly
yearly

stop? reset? action? notify? trigger? change?

💉 🏥 🚛 🛳 🚰 ⛽ 🤖 ⛑ 🌳 🌲 🌸 🌔 🍄

wheel is an extension of the foot

book is an extension of the eye

clothing is an extension of the skin

electric circuitry is an extension of the
central nervous system

The extension of any one sense
displaces the other sense and
alters the way we think
the way we see the world and ourselves

~ Marshall McLuhan, The Medium is the Message

References 📚

• thank you Sam, Ming Ding, Hwee Xian, Chinmay
• When we build talk by Wilson Minor
• Medium is the Message by Marshall McLuhan
• Web of Things at W3C
• Wireless constaint triangle by Yeo Kheng Meng
• text background image by APOD
• Web of Things architecture and thesis
• Internet of Things talk by Vlad Trifa
• Data graphs 1, 2 and 3
• MQTT & IoT protocols comparison
• Smart waste management by Pepperl+Fuchs

Buy 🔋 🔌 🎛 🕹

• Adafruit
• SparkFun
• element14
• Aliexpress
• 12Geeks
• RS Components
• Taobao
• Seeed Studio

ruby firmata library