UX Design for IoT: Interface Design 2/3




We already said it in the previous article UX Design For IoT: Designing Experiences. ⅓: most of the connected products include web interfaces or smartphones, and the way in which we interact with them has been very limited.

That’s not what we are going to talk about here. In IoT, there is another richer and more complicated world that challenges the UI / UX designer.

Combining devices that do not have a user interface (such as an intelligent thermostat or a smart plug), or voice inputs, gestures, speed, strength … with screens, sounds, or even vibrations, is something that IoT offers. So this opens a whole new opportunity for UX/UI Designers to define the way we interact with them.

Types of interactions

  • Physical controls – they are (almost) everywhere represented by pressing a button to activate something, using a switch to choose between two states or sliding controls … They are pretty great for a direct and fast control, especially when precise adjustments are required.
Aether Cone speaker
Aether Cone: turn the loudspeaker grille and push in the center of the speaker to perform actions.
  • Visual controls – almost all of the electronic devices have one LED at least as activity indicator. Connected devices require a more complex behavior than a light on or off, perhaps should you use flickers, color codes or patterns to help to understand what is happening.
Ambient Orb
The Ambient Orb uses lights of different colors to show information, for example, current energy prices
  • Screens – sometimes it takes much more than one or a set of lights to show complex information. We are familiar with phones, computers or smart TVs that have large screens and a clear UI. But there is another simpler range of devices that require different design approaches such as a liquid crystal display (LCD) that has a limited number of pixels and uses very small amounts of energy.
Xiaomi Mijia Bluetooth hygrothermograph
Xiaomi Mijia Bluetooth hygrothermograph
  • Audio – this is a very useful way for users not to have to look at the device directly, not even to be close to it. How many times have we experienced the insistent beep when our cooking robot  or washing machine has finished its cycle? Through audio we can transmit sensations such as satisfaction or urgency.
  • Voice – Both, input, and output, can be a powerful method to provide a large amount of information. We have all used car navigation systems that use voice or voice recognition on our smartphones to execute complex commands.
Alexa by Amazon
Alexa, the Amazon voice assistant
  • Tactile interactions – tactile interfaces, vibrations, shape changes … users feel something as they interact with the devices. It is inspiring to see how tactile interactions can change everyday interactions.
Reactable music
A Reactable in use making music (image: Reactable/Massimo Boldrin)
  • Gestures – gestural interactions exist both on touch screens (swipe, click) and on devices that can recognize gestures in the air. Perhaps one of the most famous examples is in the movie Minority Report, where Tom Cruise controls the interface of a system with both hands in the air. However, it is true that this type of interactions is not yet very useful and is a bit far from the real world.
Tom Cruise Minority Report
Tom Cruise in Minority Report
  • Context-Sensitive interaction – they are similar to the gestures, but they have to do with the body. Instead of gesturing, the presence of the user itself in a room, or a bus stop, can give information and improve the user experience.
  • Vision – there are interfaces that involve devices that see or respond to physical artifacts around them. Facial recognition, patterns, physical examination, all are based on vision through the device. The power of this type of interaction is that they eliminate the need of an user input. Facial recognition is much faster than having to enter a PIN.
  • Multi-modal interaction – it is what gives a name to the interaction of a connected device that can combine different types of interfaces. It refers to combinations of gestural interaction with voice, as in the prototype of Jared Ficklin “Room-E” where a room is controlled through this combination.
Room E
Jared Ficklin “Room-E” prototype

Challenges and opportunities in IoT

Adding interactivity to a device can be a cost matter. The elements that directly affect the UX such as buttons, switches, and other required components increase the bill of materials and development costs. Designers have to find the balance between easy-to-use devices and excess functionality.

On the other hand, simple devices with minimal functionalities have other disadvantages. Normally they are devices dependent on things or actions that are beyond the designer’s control since they rely on other devices for the interaction of complete functions.

Tado thermostat
Tado, the first thermostat had only one button and was based on a smartphone application for total control; the next-generation device includes a little more control on the device through two additional capacitive touch buttons


There are ways to balance the benefits and disadvantages of physical controls. Many connected devices use mobile applications or web interfaces as their main means of control. This is advantageous since they are much easier to modify and develop, which gives great agility to respond to the constant changes that occur in this sector. Aside, web application and development can count on a large community of active developers with a lot of useful resources available.

In turn, telephones and computers provide a large processing capacity that an integrated device may not support. But these may not be constantly available (lack of battery, loss of connectivity) so they are not appropriate for critical notifications.

There are many different interaction channels for the user to control their connected product. It will be necessary to study the different benefits and disadvantages to create the most appropriate interface.

New products may require unknown combinations to create a good user experience, in our hands is to experiment and explore new possibilities of interaction with a device or system.

It’s designer’s role to decide the correct compensation between device flexibility and usability But also, this decision depends on  the product strategy and to the human perception obtained from a thorough investigation (prototyping, user test …)

Designing connected products


Article written by Ana Rosa González, User Experience Manager at Barbara IoT.

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