Piezo panel touch button controller operates standalone

June 19, 2014 // By Graham Prophet
The ATB252, for touch-activated sensing on flat panels, eliminates a host processor with the facility for EEPROM configuration and Digital Direct Output (DDO) mode.

Aito BV, supplier of software-enhanced piezo (SEP) touch control technology, has announced its ATB252 AitoTouch Controller, which allows touch panel designs to be created that do not require an external host processor or other supervisory device. This feature is enabled by the inclusion of a Digital Direct Output (DDO) mode that, in addition to conventional I2C and SPI host communication interfaces, allows the ATB252 to be directly configured from an EEPROM to provide a standalone solution.

The ATB252 implements Aito's SEP technology, that allows touch buttons to be implemented on metal and other surfaces, and supports up to 6 piezo touch key inputs in combination with up to 11 LED indicators and a buzzer output. In DDO mode, six of the ATB252 pins become outputs that are directly mapped to each individual piezo input. These outputs signal touch button operation in one of several ways, which can be selected according to system requirements; so pressing a key can either cause the associated output to go high or low, or trigger an output pulse, or toggle from one state to the other with each key press.

As with other AitoTouch solutions, the ATB252 allows the piezo sensing parameters for each key to be individually configured for sensitivity, detection area and to cope with different overlay stiffness or mechanical integration conditions. Also, the LED indicator and audible buzzer responses for each button can be individually defined with a customised feedback pattern.

“The ATB252 extends the scope of AitoTouch to simpler touch control applications where the added intelligence of a host processor is not required, and where the configuration can easily be saved to low-cost EEPROM for each product design”, said Pauli Laitinen, Aito CTO and co-founder, “With this device, Aito aims to expand the replacement rate of traditional mechanical buttons, as well as capacitive ones, to a wider range of industrial and low cost appliances than ever before.”

Aito’s SEP technology allows