Piezo detection controller enables touch keys on metal surfaces

June 06, 2014 // By Graham Prophet
Providing a robust user interface for home appliances and industrial controls, Aito's software-enhanced piezo (SEP) touch control technology in its ATB250 AitoTouch Controller provides a configurable user interface for up to 11 touch buttons.

Aito's SEP technology allows the creation of seamless touch keys on any surface, replacing traditional mechanical switches and overcoming the problems of capacitive and other touch technologies that either require significant button travel or will not operate with gloved hands or through-metal panel overlays. Target markets are those where this capability adds value in design aesthetics and functionality to provide a quality user experience. Applications include: kitchen appliances, such as ovens, hobs, hoods, refrigerators, coffee machines, toasters, as well as consumer audio/video and home automation products, but also medical equipment and industrial controls, where the benefits of sealed panels and robust, reliable operation are vital.

The ATB250 controller provides a combination of input and output channels to support up to 11 piezo touch buttons, each with drivers for LED indicators to provide visual feedback, along with a single buzzer output for audible feedback. The piezo sensing parameters for each key can be individually configured for sensitivity, detection area and to cope with different overlay stiffness or mechanical integration conditions. The LED and buzzer feedback patterns can be customised for each key. For easy integration into existing hardware, the device offers SPI, I2C and DEO (Digital Encoded Output) mode interfaces for communication with the host processor.

Rene de Vries, Aito CEO and founder, explains, “We are seeing is a trend to metal touch panels and what our SEP technology offers is the design freedom to use any material, even wood, to create extremely robust switch assemblies on flat or curved surfaces of varying thicknesses. The choice of overlay material can enhance the visual appeal of the end product while the use of a seamless surface also provides protection from moisture, chemicals and other contaminants: AitoTouch offers designers the ability to create standard touch modules that can be used for multiple purposes across their product range, contributing to a reduction in overall costs.”

The ATB250 11-channel AitoTouch chip costs $0.99 (100,000). An