This document discusses the Web of Things (WoT) and the role of Firefox OS in supporting it. It proposes adding new Web APIs to Firefox OS to enable direct hardware access from JavaScript, such as a Web GPIO API and Web I2C API. These APIs would allow Firefox OS to control devices locally via their GPIO and I2C interfaces without an internet connection. The document also discusses standardizing these new APIs through the W3C to ensure compatibility across different browser implementations of the WoT.

1. Firefox OS study group tokyo 9th
Firefox OS for Embedded System and Web APIs
(English version)

2. 2/31
Self Introduction

Twitter: @masap

Embedded System Engineer（mainly Wi-Fi）

3. 3/31
Table of contents

What is WoT ?

Position of Firefox OS on WoT

Add the Web APIs for Firefox OS

Standardization of Web APIs

4. 4/31
What is WoT ?

5. 5/31
review

Today's thema is “Go for it WoT ”！

Review on WoT

6. 6/31
IoT (Internet of Things)

Connect various things to the Internet

By computers on cloud

Summarize informations

Control devices

Cloud
Things
Traffic accident
occurredControl signals,
digital signage

7. 7/31
WoT (Web of Things)

Web = HTTP ？

IoT = IP、Web = HTTP no diferent→

Application
HTTP
IP
Things
Application
Things
IP
IoT WoT

8. 8/31
WoT (Web of Things)

Web = Browser？

We can write all with JavaScript

Browser
HTTP
IP
Things
WoT
ApplicationApplication
IP
Things
IoT
C
C/Java
JavaScript

9. 9/31
Browser as a platform

“Web = Browser” is more acceptable

Accessing to things and connection to the network
could be done via Browser

JavaScript can control things and HTTP protocol

At the standard IoT, almost things will be controlled
with native languages (like C)

⇒Browser as a platform

WoT means this


10. 10/31
Position of Firefox OS on WoT

11. 11/31
Should all the things run
browser ?

Smart Endpoint vs Dumb Endpoint

This question causes debates on IoT

Should the “Things” on IoT be intelligent ?

Don' be involved in the debates. Make an layer
between them. Fog computing⇒

Smart Endpoint Dumb Endpoint
Unintelligent
- Pass the raw data to upper layer
- Do ordered actions
Intelligent
- Pass the summarized data
to upper layer
- Acts autonomously

12. 12/31
What is Fog Computing

Create a Fog Layer between Cloud and Things
Cloud
Things
Cloud
Things
Fog
Data reception server, Database,
Statistical Analytics Server, etc...
temperature, accelerometer,
Geiger-Müller counter, other sensors.
Cloud
Computing
Fog
Computing
Summarize data,
Transform format, etc...

13. 13/31
Example of Fog Layer
Cloud
Things
Fog
Urban planning by AI
Fog
Things
Notify to neighbors
Accidents statistics
Traffic accident
occurredControl signals,
digital signage

14. 14/31
Fog Computing Products

Cisco

Cisco proposes Fog Computing

Cisco has “Cisco Iox” Fog Development Platform

It's too expensive for almost companies

15. 15/31
Fog with Firefox OS
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Firefox OS

Fog with Firefox OS

Firefox OS has more hardware access Web APIs than
Chrome、Safari、IE

16. 16/31
What is required for Fog ?

Hardware access via Firefox OS

Firefox OS is built with Web Technology

There is no mechanism like the Android NDK

Can not use native language

Hardware control with JavaScript is required

17. 17/31
The way to control Things via
Web (1)

Via Network

HTTP, nodejs, WebSocket, WebRTC

This way is already used
sensorFirefox OS
network

18. 18/31
The way to control Things via
Web (2)

Control locally

Without network connection

There is not any path for this
⇒ Let them make API
⇒ Create new Web APIs !
sensor
Direct connectionFirefox OS

19. 19/31
Add the Web APIs for Firefox OS

20. 20/31
What is Web API ?

“Web API” has two means

Services on the Web

Twitter API、Youtube API、...

JavaScript API on the Browser (I expect this today)

navigator.getUserMedia, navigator.geolocation, …

21. 21/31
Hardware access Web API

What will we create ?

Create navigator.hardwareaccessxxx API like
navigator.getusermedia

How to create new Web API ?

Modify Firefox

22. 22/31
Modify Firefox

On Firefox, Gecko implements Web APIs

So will add some new code to Gecko to create some new
Web APIs

gecko/dom/geolocation etc...
Gecko
Web Application
Web API

23. 23/31
Required Web API

Popular hardware for IoT

input: sensor

output: motor

Such hardwares has GPIO or I2C interface

Create Web API for GPIO and I2C

24. 24/31
What is GPIO ?

What is GPIO ?

General Purpose Input/Output

Pins connects computers and peripherals

Configure on/of or read on/of of specific pin

Control on/of of LEDs or motors

25. 25/31
What is I2C ?

What is I2C ?

Bus for serial communication

Enables you to read/write a value

GPIO deals only on/of

Almost sensors and motors has this interface

26. 26/31
Web GPIO API

Web GPIO API (part)

navigator.requestGPIOAccess()

Get a GPIO access object

gpio.ports.get(GPIO pin number)

Get a GPIO port object

port.write(value)

Write to a port

port.read()

Read from a port

27. 27/31
Web I2C API

Web I2C API (in progress)

navigator.requestI2CAccess(device_name,address)

Get an I2C device access object

i2c_device.write/read(register address, value);

Write to a register, read from a register

example

Drive a motor with DRV8830
var i2c_device =
navigator.requestI2CAccess("/dev/i2c-1", 0x64);
i2c_device.write(0x00, 0xfd);

28. 28/31
Standardization of Web APIs

29. 29/31
Standardization

WoT is not only Gecko

WoT with V8 or Trident

Standard way is required

Web GPIO is discussed on W3C Browsers and
Robotics Community Group
http://www.w3.org/community/browserobo/

30. 30/31
Example of discussion

Promise vs Return value

Promise

merit: async enabled

demerit: deep nest

Return value

merit: shallow nest

demerit: async disabled

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end