The TouchKey Click Board™ features four capacitive pads powered by the TTP224 touchpad detector IC. TTP224 chip comes with multiple operating modes that allow the user to configure how the buttons will work. The capacitive pads can be toggled even when placed under a layer of glass or paper. TouchKey Click Board™ outputs four interrupt signals: OUTA, OUTB, OUTC and OUTD in place of default MikroBUS RST, AN, PWM and INT pins, respectively. It features three onboard jumpers that enable the user to configure several operating modes of the TTP224 IC, including fast mode or low power mode, direct or toggle mode, enable/disable multi-key input, and so on. TouchKey Click Board™ is designed to work on either a 3.3V or 5V power supply.
It works as an ideal replacement for mechanical switches and buttons and being capacitive, it can register inputs through paper or glass.