An End-to-End Web IoT Demo Using Mozilla Gateway

Imagine that you are on your way to a holiday home you have booked. The weather is changing and you might start wondering about temperature settings in the holiday home. A question might pop up in you mind: “Can I change the holiday home settings to my own preference before reaching there?”

Today we are going to show you an end-to-end demo we have created that allows a holiday maker to remotely control sensor devices, or Things in the context of Internet of Things, at a holiday home. The private smart holiday home is built with the exciting Mozilla Things Gateway – an open Gateway that anybody can now create with a Raspberry Pi to control Internet of Things devices.  For holiday makers, we provided a simple Node.js holiday application to access Things via Mozilla Things Gateway. Privacy is addressed by introducing concepts of Things ownership and Things usership, which is followed by the authorization work flow.

The Private Smart Holiday Home

The private smart holiday home is the home for Gateway and Things –

Things Gateway

One of the major challenges in the Internet of Things is interoperability. Getting different devices to work nicely with each other can be painful in a smart home environment. Mozilla Things Gateway addresses this challenge and provides a platform that bridges existing off-the-shelf smart home devices to the web by providing them with web URLs and a standardized data model and API [1]Implementations of the Things Gateway follows the proposed Web of Things standard and is open sourced under Mozilla Public License 2.0.

In this demo, we chose Raspberry Pi 3 as the physical board for the Gateway.  Raspberry Pi 3 is well-supported by the Gateway community and has been a brilliant initial choice for experimenting the platform. It is worth mentioning that the Mozilla Project Things is not tied only to the Raspberry Pi, but they are looking at supporting a wide range of hardwares.

The setup of the Gateway is pretty straightforward. We chose to use the tunneling service provided by Mozilla by creating a sub-domain of mozilla-iot.orgsosg.mozilla-iot.org. To try it yourself, we recommend going through the README file at Gateway github repository.  Also a great step-by-step guide has been created by Ben Francis on “How to build a private smart home with a Raspberry Pi and things Gateway”.

Things Add-ons

The Mozilla Things Gateway has introduced an Add-on system, which is loosely modeled after the add-on system in Firefox, to allow for the addition of new feature or device such as an adapter to the Things Gateway. The tutorial from James Hobin and Michael Stegeman on “Creating an Add-on for Project Things Gateway” is a good place to grab the concepts of Add-on, Adapter, Device and to start creating your own Add-ons. In our demo, we have introduced fan, lamp and thermostat Add-ons as shown below to support our own hardware devices.

Phil Coval has posted a blog explaining how to get started and how to establish basic automation using I2C sensors and actuators on gateway’s device. It is the base for our Add-ons.

Holiday Application

The holiday application is a small Node.js program that has functionalities of a client web server, OAuth client and browser User Interface.

The application consists of two parts. First is for the holiday maker to get authorization from the Gateway for accessing Things at the holiday home. Once authorized, it moves to the second part, Things access and control.



OAuth client implementation is based on simple-oauth2, a Node.js client library for OAuth2.0. The library is open sourced under Apache License, Version 2.0  and available at github.

The application code can be accessed here. The README file provides instructions for setting up the application.

Ownership and Usership of Things

So here we have it, the relationships among Things owner, Things user, third party application, Gateway and Things.

whole_picture2

  • The holiday home owner is the Things Gateway user and has full control of the Things Gateway and Things.
  • The holiday maker is a temporary user of Things and has no access to the Gateway.
  • The holiday home owner uses the Gateway to authorize the holiday maker  accesses to the Things with scopes via gateway.
  • Holiday application accesses the Things through the Gateway.

User Authorization

The Things Gateway provides a system for safely authorizing third-party applications using the de-facto authorization standard OAuth 2.0. The work flow for our demo use case is shown in the diagram below –

The third party application user, the Holiday App User in this case, requests authorization to access the Gateway’s Web Thing API. The Gateway presents the request list to the Gateway User, the holiday home owner, as below –

With the holiday user’s input, the Gateway responds with an authentication code. The holiday application then requests to exchange the authentication code to a JSON Web Token (JWT) . The token has a scope that indicates what accesses were actually granted by the holiday home owner. It is noted that the granted token scope can only be a subset of the request scope. With the JWT granted, the holiday application can access the Things that the user is granted to.

Demo Video

We also created a demo video which tailored together different parts we talked above, and is available at https://vimeo.com/271272094.

What’s Next?

The Mozilla Gateway is a work in progress and is not yet reached production use stage.  There are a lot exciting developments happening. Why not get involved?

Ziran Sun

Author: Ziran Sun

Ziran Sun is an Open Source Engineer at Samsung Research UK. She has been involved in a few open source projects, including webinos, blink/chromium and IoTivity. Currently Ziran is looking at web IoT and related areas.