In the ”Internet of Things” (IoT) vision the physical world blends with virtual one, while machine-to-machine interaction improve our daily life. Clearly, how these virtual objects are exposed to us is critical, so that their user interface must be designed to support the easiness of usage that is driven by the users’ needs, which is different from what machines requires. These two requirements must be solved, and an integrated solution should emerge, if we want to bring the IoT to the 50 billions network that is predicted to became in the next years. In this talk, you will see how these requirements cannot be met by the same communication protocol, as the user interfaces dictates a way of communication that is no suitable for the "machines". We will analyze what are the state-of-art protocols for both machines and users, and finally we will propose a solution to solve this problem.

1. @matteocollina
matteocollina.com
Making things
that work with us!
Codemotion Venezia 2012/11/17

2. Smartphones are
changing the world

3. How many people will own
a smartphone by 2014
1.000.000.000

4. Did you see
it coming
http://www.flickr.com/photos/12738000@N00/360231193/

5. Steve
did.
http://www.flickr.com/photos/noppyfoto/6216399465/

6. Thanks.
http://www.flickr.com/photos/noppyfoto/6216399465/

7. They didn’t!
...

8. What's next
(hint: it's a big number)
50.000.000.000

9. 50.000.000.000
1.000.000.000

10. "Things"

11. http://www.flickr.com/photos/adactio/2337914481
50.000.000.000
interconnected
"things"
by
2020

12. Social Web Of
Things Video
http://www.youtube.com/watch?v=i5AuzQXBsG4

13. Let's experiment

14. http://www.flickr.com/photos/jurvetson/2798315677

15. Goal:
Monitor my
house
temperature

16. I want to
chat with
my house

17. >: hi house
hi matteo
>: what's the
temperature?
36

18. >: 4 8 15 16 23 42
If you don’t
understand
this, you are
not a geek!

19. Enter Hubot
Hubot © 2012 GitHub Inc. All rights

20. A programmable robot
that is controlled through
chat
Hubot © 2012 GitHub Inc. All rights

21. We can supercharge our house with hubot

22. We can supercharge our house with hubot
How
module.exports = (robot) ->
robot.respond /what’s the temperature?/i, (msg) ->
msg.http("http://mchouse.it/temperature")
.header("Accept", "application/json")
.get() (err, res, body) ->
msg.send JSON.parse(body)

23. In order to ask our temp
to hubot, we need to:
1. sense the temp
2. get the temp on the web
3. build a web API

24. From Hubot, I want to do
the equivalent of:
>: curl http://mchouse.it/temp
What about JSON

25. We are building an API
In Italy,
“API” means
“bees”
http://www.flickr.com/photos/theseanster93/4056815767

26. What do we need to
sense my house
temperature

27. Arduino is an open
source microcontroller,
that you can use to
hack things
http://www.flickr.com/photos/mattrichardson/5029708468/

28. We add a sensor to an Arduino
TMP
36
TMP
36

29. We add an ethernet shield to
connect to the Internet
TMP
36
http://www.flickr.com/photos/snootlab/6052465980/

30. What protocol do we use
to push our temperature
to our API?
HTTP POST

31. HTTP is slow and safe
http://www.flickr.com/photos/clearlyambiguous/48185613/

32. We need a
fast, binary
protocol
http://www.flickr.com/photos/grrphoto/305649629

33. likes binary

34. What if we
need to
interconnect
our things?

35. To build a
social web of
things we
need to react
to events.

36. We need a
publish/subscribe
pattern.

37. HTTP

38. Devices need:
• binary protocol
• publish/subscribe

39. Binary vs REST
M2M protocols are “Things” should
ad-hoc, and interact with our
researchers and lives, and all the
businesses focus on technology should
low level problems. be built to make
them easy to use.

40. • “things” exposed • “things” exposed
with binary protocol to the web
• publish/subscribe • request/response
• topics as the naming • URIs as the
system naming system

41. MQTT is the
state of art
protocol for the
Internet of
Things

42. Mosquitto
Really Small
Message Broker

43. • the base element of the protocol is a topic
• devices and other systems can publish or
subscribe to topics

44. How to use
on

45. Step 1: download
PubSubClient, the
library for

46. on Arduino: Setup
String server = String("qest.me");
PubSubClient client =
PubSubClient(server,
1883,
callback);

47. on Arduino: publishing
if (!client.connected()) {
client.connect("arduino");
}
client.loop();
char s[10];
itoa(get_temperature(), s, 10);
client.publish("temp", s);

48. on Arduino: publishing
if (!client.connected()) {
client.connect("arduino");
}
client.loop();
This is called a topic,
and it is where we publish
chars[10]; MQTT.
things on
itoa(get_temperature(), s, 10);
client.publish("temp", s);

49. speaks
, Hubot speak HTTP

50. speaks
Communication
, Hubot speak HTTP

51. Discover
QEST
qest.me

52. QEST
HTTP Clients MQTT Clients
• MQTT broker
• REST interface
REST Server MQTT Server
• HTTP semantics QEST
• no QoS Data Layer
• built in node.js
• crafted by me Redis

53. QEST : MQTT to REST
• retains every message received
client.publish("temp", "30");
• every topic has its own URI: /topics/<NAME>
curl -H "Accept: txt"
http://qest.me/topics/temp

54. QEST : REST to MQTT
• transform every HTTP PUT received to a
MQTT message
curl -X PUT -d '{ "housetemp": 42 }'
-H "Content-Type: application/json"
http://qest.me/topics/temp
• devices can listen directly to MQTT topics
void callback(char* topic, byte*
payload, int length) {
...
}
PubSubClient(server, 1883, callback);
client.subscribe("temp");

55. state-of-art QEST-based
approach to IoT apps solution to IoT apps
Web App Web App
Bridge
QEST
IoT
Device
3 2 1 0 9 8 7 6 5 4 3 2 1 0
GND
SCL
AREF
SDA
1 1 1 1 DIGITAL
RX
TX
PWM
PWM
PWM
PWM
PWM
PWM
L
TX
Arduino UNO ON
Broker
RX
1
ICSP
www.arduino.cc
RESET
IOREF
POWER ANALOG IN
3V3
5V Gnd Vin 0 1 2 3 4 5
Device
3 2 1 0 9 8 7 6 5 4 3 2 1 0
GND
SCL
AREF
SDA
1 1 1 1 DIGITAL
RX
TX
PWM
PWM
PWM
PWM
PWM
PWM
L
TX
RX
Arduino UNO ON
1
ICSP
www.arduino.cc
RESET
IOREF
POWER ANALOG IN
3V3
5V Gnd Vin 0 1 2 3 4 5

56. QEST : Scalability
HTTP/MQTT Clients
Load Balancer
REST Server MQTT Server REST Server MQTT Server
QEST
Data Layer
... QEST
Data Layer
Redis

57. Do you like
Spaghetti
Code?
JavaScript Apps are
often a mess
We mix logic with
presentation with
persistance.
Is QEST different?
http://www.flickr.com/photos/mpirotta/4944504834

58. QEST:
Built BDD-style, with
Cucumber-js and mocha
Continuous Integration
based on Travis-CI
Written in CoffeeScript
Patches are welcome!
http://www.flickr.com/photos/mpirotta/4944504834

59. Let’s ask something
to my house!
http://www.flickr.com/photos/oneaustin/1261907803

60. Hubot Integration
module.exports = (robot) ->
robot.respond /qest check ([a-z0-9A-Z]+)/i, (msg) ->
topic = msg.match[1]
if topic?
msg.http("http://qest.me/topics/#{topic}")
.header("Accept", "application/json")
.get() (err, res, body) ->
msg.send JSON.parse(body)
else
msg.send "No topic specified"
Hubot © 2012 GitHub Inc. All rights

61. Security Issues
• What devices can a user monitor?
• What devices can 'listen' to the
state of other devices?
• Who can access the devices state?
• Is the communication secure?

62. We need to
interconnect Users
Social profiles to
the Devices!

63. We need OAuth
for Devices!
I’m
working on
it!!

64. try
QEST
qest.me

65. TL;DR
• The Internet of Things
will be big
• Devices need binary
and pub/sub protocols
• Devs need HTTP API
• QEST does both

66. Matteo Collina
Software Engineer @
Mavigex
Ph.D. Student @
University of Bologna
@matteocollina matteocollina.com

67. Credits
• Font Awesome for the
Icons.
• Flickr for LOTS of CC
images :).
• Balsamiq Mockup for
the iPhone Mockup

68. @matteocollina
Thank You!
Matteo Collina (matteo.collina2@unibo.it)
http://www.flickr.com/photos/axel-d/479627824/

69. Any Questions?
http://www.flickr.com/photos/alexindigo/1606826416