1. Smart Block: A Visual Programming Environment for SmartThings
Nayeon Bak, Byeong-Mo Chang
Dept. of Computer Science
Sookmyung Women's University
Seoul, Republic of Korea
{b_newyork,
Kwanghoon Choi
Dept. of Electronics and Computer Engineering
Chonnam National University
Gwangju, Republic of Korea

2. 01 Introduction
02 Visual block language Smart Block
03 Visual programming environment for Smart Block
04 Implementation
05 Conclusion and Future works
06 QnA

3. Introduction

4. Fig. Structure of SmartThings
SmartThings is one of the most widely-used open developer platforms for IoT with a high number of applications among currently available platforms [1](𝑆𝑚𝑎𝑟𝑡𝑇ℎ𝑖𝑛𝑔𝑠 𝐷𝑒𝑣𝑒𝑙𝑜𝑝𝑒𝑟 𝐷𝑜𝑐𝑢𝑚𝑒𝑛𝑡𝑎𝑡𝑖𝑜𝑛 𝐻𝑜𝑚𝑒𝑝𝑎𝑔𝑒, )
It also supports a wide range of smart devices which work through a central hub
SmartApp is an application that provides automatic service by using smart devices
SmartThings App is a mobile application managing SmartApps and smart devices
Smart devices include lights, cameras, locks, thermostats, and various sensors.
Fig. Structure of SmartThings

5. SmartApp
SmartApp is a small Groovy-based program that allows users to automate their homes using smart devices
A user installs SmartApp on their SmartThings mobile application, and configures it with smart devices
SmartApp is executed in the SmartThings cloud
It is executed in response to various schedules or events from smart devices
SmartThings IDE(Integrated Developer Environment)
Developers can build and install new SmartApps in the SmartThings IDE
SmartThings IDE provides a set of tools to manage their SmartThings account, builds and installs SmartApps
말로 preference에서는 이 앱에서 사용할 devic들을 정의하는 것이고 predefined and callback에서는 어떤 device의 이벤트가 일어났을때 어느 핸들러가 처리할지 정의하고 eventhandler에선 이벤트가 발샐할때 어떤 일을 하는지 작성하는 부분이다.

6. SmartApp Example
When the lock gets unlocked, if a user is present at home, then turn the light on and play music
Definition
Preferences
Predefined Callbacks
Event Handlers
말로 preference에서는 이 앱에서 사용할 devic들을 정의하는 것이고 predefined and callback에서는 어떤 device의 이벤트가 일어났을때 어느 핸들러가 처리할지 정의하고 eventhandler에선 이벤트가 발샐할때 어떤 일을 하는지 작성하는 부분이다.

7. Motivation Users can have difficulty in writing SmartApp in Groovy
A visual block language can help users make programs easily by assembling building blocks graphically rather than by specifying them textually
We propose a visual block language called Smart Block for IoT, especially for SmartThings
Users can develop SmartApp easily in Smart Block, even though they are not expert programmers

8. Smart Block
We deigned and implemented a visual block language Smart Block
Also we develop a visual programming environment and compiler for Smart Block.
Users can build SmartApps by dragging and dropping blocks in this environment easily
Implementation
A visual programming environment for Smart Block is implemented with
Blockly is a client-side JavaScript library which can be used for creating visual block languages and programing environment [2](𝐵𝑙𝑜𝑐𝑘𝑙𝑦: 𝐴 𝑙𝑖𝑏𝑟𝑎𝑟𝑦 𝑓𝑜𝑟 𝑏𝑢𝑖𝑙𝑑𝑖𝑛𝑔 𝑣𝑖𝑠𝑢𝑎𝑙 𝑝𝑟𝑜𝑔𝑟𝑎𝑚𝑚𝑖𝑛𝑔 𝑒𝑑𝑖𝑡𝑜𝑟𝑠, )

9. Visual block language Smart Block

10. SmartApp with Smart Block
when the lock gets unlocked from locked,
if a user is present,
then turn the light on and play music
핵심 아이디어 말하는 곳
Smart Block

11. Key Idea SmartApp Event when the lock gets unlocked from locked,
Condition
Action
when the lock gets unlocked from locked,
if a user is present,
then turn the light on and play music
Smart Block based on IoTA calculus
Event
Condition
Action

12. IoTA calculus Smart Block is designed based on IoTA calculus
IoTA calculus is a core calculus for Internet of Things Automation that generalizes Event-Condition- Action (ECA) rules for home automation [3](𝑁𝑒𝑤𝑐𝑜𝑚𝑏, 𝑒𝑡 𝑎𝑙., )
SmartApp can be represented by ECA rules with Smart Block
ECA rule can specify which action is triggered by event, if the given condition is satisfied
Example
Event
Condition
Action
when the lock gets unlocked from locked,
if a user is present,
then turn the light on and play music.

13. Demo
We show how to build a sample SmartApp with Smart Block

14. ECA block, EA block ECA block ECA block represents one rule
It should be connected with Event block, Condition block and Action block
EA block
EA block is an ECA block whose condition is always true

15. Event block Stands for the event from a device Example
1. This Event block means an event of unlocked from locked on the lock1 device
2. This Event block means timer at 8:00 AM

16. Condition block
Checks whether the value of a boolean algebra over a state on devices is true or not
If the result is true, the action will be performed
Example
1. This Condition block checks whether the value of presenceSensor named presence1 is present
2. This Condition block checks whether the temperature rises above 22 degrees

17. Action block Stands for the action
Action blocks can be linked together in a line as below, which will be performed in sequence
Example
1. This Action blocks means turning on a light1 device and playing music on music player1
2. This Action block mean to send a push message which is “The unexpected guest!”

18. All building Blocks in Smart Block
ECA blocks
ECA block
EA block
Event blocks
44 Event Device blocks
Event Location block
3 Event Schedule blocks
Grouping Event block
Condition blocks
44 Condition Device blocks
7 Boolean algebra blocks
2 Grouping Condition blocks
Action blocks
28 Action Device blocks
3 Action SMS blocks
8 Action Timer blocks
Grouping Action block

19. Visual programming environment for Smart Block

20. Visual programming environment for Smart Block
Users can create SmartApps in this environment by dragging blocks from the toolbox and dropping blocks in the workspace
Users can choose smart devices at the smart device table
Smart devices are classified as the alphabetical order
Users can collect smart devices which are used often in ‘THINGS’ category
Also, SmartApp is compiled in this environment
Smart device
table
Workspace
Toolbox
smart device와 work space

21. Demo
We show how to build the SmartApp consisting of two ECA rules with Smart Block
when the locked door gets unlocked
if the user is present at home
then turn on the light and play music
Frist ECA Rule
when the locked door gets unlocked
if the user is not present at home
then ring alarm and send the push message
Second ECA Rule
Is get?

22. Demo
smart device와 work space

23. Compiling Process Overview of Compiling process
SmartApp Code is generated from the completed blocks
We take a two-pass approach
AST Constructor : Constructing AST from the completed blocks
Code Generator : Generating SmartApp Code from the AST

24. Generated SmartApp Code

25. Implementation

26. Implementing Process of Smart Block
Compiler is implemented based on Generator stub produced by Blockly Developer Tools
AST Constructor
Code Generator
Visual programming environment is designed and implemented with custom blocks and on top of HTML, JavaScript, and CSS and by using Blockly Developer Tools
Definition code
Toolbox
workspace
Custom blocks for Smart Block are designed and implemented by using Blockly Developer Tools
Definition code
Visual programming environment is built on top of HTML, JavaScript, and CSS
Definition code for Custom block
Toolbox XML code
Workspace JavaScript code
Compiler is implemented based on the default Code Generator from the open source of Blockly
AST constructor
New code generator

27. Blockly Developer Tools
Blockly Developer Tools gives the definition codes for the custom blocks and the toolbox that contains them, as well as the workspace

28. Custom Block
The definition code of ECA block are produced by building an internal organization of ECA block in Blockly Developer Tools
Fig. ECA block
Fig. definition code of ECA block
Fig. internal organization of ECA block

29. Visual Programming Environment
Visual programming environment is built on top of HTML, JavaScript, and CSS
Also, it is implemented with custom blocks, toolbox and workspace
Blockly Developer Tools provides the XML code for toolbox and the JavaScript for workspace

30. Complier : AST Constructor
We develop AST constructor by extending the default Code Generator
AST constructor generates the AST of each ECA block by parsing
The AST of ECA block is made up of nodes for Event, Condition and Action
ASTs 아니라 노드아님?

31. AST of ECA blocks
Workspace is the root node of the AST for ECA blocks for SmartApp
AST of ECA block is a child node of workspace node
The AST constructor returns the AST of the ECA blocks

32. Complier : Code Generator
We develop a new Code Generator
New Code Generator generates the actual SmartApp code by traversing the AST of the ECA blocks
에니메이션 넣을까?

33. Conclusion and Future works

34. Conclusion and Future works
We designed a visual block language Smart Block
We developed a visual programming environment and the compiler for Smart Block
So, Users can build SmartApps by dragging and dropping blocks in this environment
We are going to extend Smart Block by implementing new features
library for data structure
security
We will extend Smart Block to support not only SmartThings but also other IoT platforms

37. All building Blocks in Smart Block
Event Block
Condition Block
Action Block
에니메이션 넣을까?

38. Detail of AST Rule Event Condition Action name of device value
Action list
에니메이션 넣을까?
Event
name of device value
capability of device
attribute
detail of event
from to
Condition
the right value
the left value
operator
result
Action
name of device value
capability of device
command
method
args

39. Smart Block
Turn your lights on when motion is detected
에니메이션 넣을까?

40. Smart Block
turn heater on when the temperature drops below 8 degrees and turn fan on when the temperature rises above 22 degrees.
에니메이션 넣을까?

41. Expressiveness of Smart Block
Referenced by Iota: A Calculus for Internet of Things Automation
We surveyed home automation applications coded in general-purpose languages from app stores, user forms, and Github, and found that most are expressible in an ECA rule system
We found that programs from existing ECA languages were easily translated to IoTA, and larger programs from general purpose languages translated to much smaller IoTA programs
에니메이션 넣을까?

42. SmartThings
SmartThings has the largest number of apps among currently available smart home platforms
It supports a broad range of devices including motion sensors, fire alarms, and door locks
And with SmartThings, we could focus on study about the software for IoT
에니메이션 넣을까?

43. Library for data structure
SmartApps can store small amounts of data using a map-like API, and retrieve this data in later executions
We will implement the custom block for data which will affect the next execution
에니메이션 넣을까?

44. Security
By following the guidelines of SmartThings, Smart Block will generate SmartApp code
Such as
Subscriptions should be clear
Do not hard-code SMS messages
Code should be readable
Don’t repeat yourself
Methods should serve a single purpose
Do not submit unused code
Do not use offensive, profane, or libelous language ….
에니메이션 넣을까?
Fig. Code Review Guidelines and Best Practices