Problem

Despite the rapid development of smart home system, it is still not very pervasive to most people. The main reasons are:

  • People are unwilling to download too many apps on their phones.
  • Smart appliances can be very expensive.

Solution

Here we present WeHome, a smart home system based on WeChat, the most popular social media in China. WeHome dedicates to helping users conveniently control normal appliances. The main functions are:

  • Gathering environment information, such as temperature.
  • Turning on / off appliances.
  • Adjusting light brightness.
  • Setting timers for appliances.

Process

This project mainly focused on technology development.

Logistics

Team Members

  • Yunxi Tang
  • Bin Huang
  • Jianfeng Shi

Time Frame

  • May. 2015 — May. 2016

Personal Contribution

  • User Research
  • Solution Design
  • Hardware Development
  • User Testing
  • Solution Presentation

Research

survey icon

Launched a survey to gather information about users

literature review icon

Conducted literature review on existing products and technologies

From survey results, we found most people are reluctant to download apps, especially when it comes to home security. And some people think it's not worthy to buy smart appliances if they cost too much.

We also identified user needs of smart home system, including:

  • Monitoring interior environment, such as temperature, humidity, and smoke alarm.
  • Controlling switches of appliances.
  • Setting timers for certain appliances, such as turning off light in 15 minutes after sleeping.
  • Enabling appliances to automatically adjust themselves according to interior environment, such as turning on fan if temperature is too high.

Due to time limits, we decided to focus on highlighted points.

In addition, we conducted thorough research on existing products, and determined the technologies that we were going to use.

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WeChat
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ZigBee

Survey

The survey was launched online. We had 102 participants who took the survey. Based on their feedback, we identified pain points below.

  • Some participants think smart appliances are expensive, and they can still live a good life with normal appliances.
  • Some participants find it upsetting to choose apps without knowing which one actually works.

We also identified several functions that people mostly demand. The following graph is presenting our main findings.

survey pie chart

Literature Review

Based on our research on existing products and technologies, we found out that wireless is a crucial requirement for smart appliances. We compared several wireless technologies and eventually decided to use ZigBee as our core technology, since it is safer and more power-saving. And these two advantages are very important to smart appliances. The following chart compares different wireless technologies in several weighted aspects.

zigbee, wifi, bluetooth comparison

We also decided to use WeChat as our application platform due to the reasons below.

  • WeChat is the most popular social media in China.
  • It provides developers and designers with big development space. They can create plenty of innovative applications on WeChat.

Design

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Structured our original system design

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Paper-sketched our physical prototype

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Asked feedback from experts

In the end, we preliminarily decided our system would contain the following core functions.

switch icon

Turn on / off appliances

light icon

Adjust light brightness

temperature icon

Monitor temperature and humidity

timer icon

Set up timers for appliances

To provide users more control freedom, we developed 3 control modes, including:

voice control mode icon

Voice Control

text-input control mode icon

Text-input Control

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Interface Control

Structure Design

This session was to specify our system functions, structuring system frame. With survey results, we made informed decisions about functions as follows:

  • Turn on / off appliances including lamp, fan, and humidifier. These appliances are often used in people's daily life.
  • Adjust light brightness in 5 levels. It will be thoughtful when doing different activities, for example, reading, and sleeping.
  • Monitor interior environment temperature and humidity. Many people care about temperature and humidity, so they can make adjustments.
  • Set timers for fan, lamp, and humidifier. Many people have this need, for example, it would be better if they can turn on the fan before they get home in a hot day or turn off lamp in several minutes after sleeping.

We also structured our system frame, determining connection details from WeChat to appliances.

framework of system

Paper Sketch

To tackle the problem that most smart appliances are too expensive, we managed to "update" normal appliances by using smart sockets. This smart socket will contain ZigBee inside. We paper-sketched our socket prototype as follows.

Expert Feedback

After finished the original design, we asked feedback from experts about the feasibility and novelty. The experts gave us positive opinions. They also helped us confirm that the functions we planned to implement are feasible.

Prototype

This prototype contains two parts: physical prototype (ZigBee development) and software prototype (WeChat development).

For physical prototype, we reformed sockets and upgraded them to smart sockets.

For software prototype, we utilized WeChat Official Account to implement our 3 control modes.

voice control

Voice Control Mode

text input control

Text-input Control Mode

interface control

Interface Control Mode — Phone

We also implemented interface control on tablet, which is even better to control.

interface control on tablet

Interface Control Mode — Tablet

Evaluation

After we finished the prototype, we recruited several users to go through our prototype. By conducting user testing, we got their impressions and identified issues in our design.

3 control modes icon
Control Modes

Voice control, text-input control, interface control

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Participants

Each participant tested all three control modes in random order

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Metrics Measured

Learnability, efficiency, error and satisfication

Results

The graphs below is an overall evaluation on our design. We found out:

  • Our system is easy to learn in all three control modes, the instruction is very clear for users to understand.
  • Poor internet can impact on our system a lot, slow internet transmission leads to slow feedback, which minimizes user experience.
  • Interface control is the most intuitive control mode, compared with other two control modes.
  • Users expect more functions in this system, for example, fire alarm, and automatic adjustment.
evaluation result

Recommendations

Based on the feedback we received, we provided the following recommendations for further improvement:

  • Implement more sensors to sense environment information, for example, smoke and luminous intensity.
  • Realize the functionality of automatically adjusting appliances according to environment change, for example, turn on or off fan according to temperature.
  • Optimize the design of our socket, currently the appearance of smart sockets is poorly designed
  • Implement the functionality of privacy control, use account and password to make multiple users control their own appliances separately but in one official WeChat account.
  • Optimize the user interface, provide feedback when users use certain function.
  • Implement the functionality of adding or deleting appliances by user self, provide users more freedom to control their appliances.

Conclusion

As a sophomore, getting involved in a project like this can be really exciting and also challenging. This was the first time that I actually participated in each step of the whole process, from research to development, and eventually presenting our prototype to industry people.

During this project, I practiced my skills in both design and coding. The most important thing I acquired was the ability to solve problems independently. I learned how to adjust myself and find the solution when things are stuck. Being patient and positive, you will finally sort it out!