Building a Smarter Human Interface with Silicon Labs
- click to enlarge
The phrase “Human Interface” has suddenly become part of the lexicon of the technology industry. At its most basic level, this phrase is used to describe not only the aesthetics of a device, but, more importantly, the process by which a device responds to human interaction. While not a new concept, the availability of enabling technology that can revolutionize the way we interact with consumer electronics products and an urgency to incorporate this technology demonstrates the increased importance consumers are placing on interface design.
What defines good human interface design?
And how can system designers implement a smarter, friendlier and more intuitive solution? It is helpful to view a human interface simply as a set of functional interactions with end users and their surroundings. These interactions can be subdivided into two logical groupings: inputs and outputs.
Input events are those in which a user causes, either directly, indirectly or even inadvertently, a specific action to be performed. Examples of input events are:
- Touch detection – single finger touch, multi-finger touch, finger slides, taps, etc.
- External stimulus detection – proximity, motion, hand waving, voice, etc.
- Environmental detection – ambient light, temperature, etc.
- Physical detection – rotation, inclination, shock, vibration, etc.
However, it is equally important to tie input events to a tangible output event because the output event informs the user of an action that has taken place as a result of the input provided. (Sometimes input conditions result in a non-event.) Examples of output events include:
- Switching items on or off – screens, speakers, lights, safety features, etc.
- Adjusting controls – volume, backlight, brightness, stabilization, etc.
- Providing tactile feedback – auditory (“hear”), visual (“see”), haptic (“feel”), etc.
The types of input events and output responses desired will vary greatly as they depend on the type of device being built.
Why incorporate capacitive sensors in my human interface design?
The answer to this question is straightforward: Low cost and high reliability. These benefits stem from the nature of the implementation of the capacitive sensor. It is nothing more than a PCB trace, thus reducing the number of parts, materials and assembly needed. In additions, the buttons implemented with capacitive sensors have no moving parts so the end product becomes more robust mechanically.
By using an interconnected subsystem closely tied together via a flexible, software-configurable platform, it is possible to create a cost-effective capacitive sensor-based human interface implementation that is both functional and scalable. As market needs change and as new ideas emerge, firmware can be adjusted to quickly and easily implement these changes without the need to re-architect the entire system. In addition, by leaving some GPIO pins on the MCU reserved for future use, it is also possible to quickly make hardware additions while leaving the core architecture the same.
One of the hardest challenges that system designers face is envisioning what a compelling human interface solution looks like. By breaking the problem into a series of inputs and outputs and by using a scalable architectural framework, designers can create solutions that go a long way toward meeting the ever-changing definition of human interface.
Who can help me with my human interface design?
Silicon Labs offers the QuickSense™ human interface portfolio, and is uniquely positioned to be the only supplier offering MCUs and sensing technologies with a common software environment to program, debug, and analyze proximity sense, ambient light sense and capacitive touch sense solutions. The QuickSense family of products offers the fastest sensing rates, the highest sensitivity, and an intuitive and easy-to-use development tool called QuickSense Studio. The human interface portfolio includes the Si1102 and Si1120 Infrared Proximity Sensors: the industry’s most sensitive active infrared proximity sensors which enable innovative touch-less human interface applications with ultra-low power advantages. In addition, the C8051F8xx family of capacitive sensing MCUs provides an easy and reliable solution for capacitive buttons, sliders, wheels and capacitive proximity sensing.