Today’s IoT devices use at least one of these three different UI approaches:

Invisible

Some IoT devices are so subtle that we usually don’t notice them at all. For example, many thermostats and alarms are designed to only demand our attention when there is some kind of urgency. When devices are smart enough to automatically adapt to our context and goals, no interface is often the best interface.

Physical

No matter how subtle, we might still want to actively interact with IoT devices occasionally. Most devices need some kind of physical UI in case some people don’t have the right apps or the wifi goes down. This can be a few buttons, a tiny display or some LEDs and minimal audio output that indicate different states. Still, the physical UIs of smart devices are often limited for aesthetic reasons, to avoid excessive components and to save energy. This is also why they often lack screens.

Remote controlled

Since we carry screens in our pockets anyway, the UIs of smart devices are often outsourced to “companion apps” on smartphones. This approach opens up a lot of potential for creative industrial design as well as innovative software design. Installing one app for each IoT device works well when we only interact with a limited number of devices. However, this approach won’t scale once we want to adjust different lights, audio systems, alarms or climate solutions in numerous locations.