The TTP224 is a touch pad detector IC which offers 4 touch key. The touching detection IC is designed for replacing traditional direct button key with diverse pad size. Capacitive touch allows electronics to sense when your finger is within a few millimetres of a surface to simulate a button “press” just like how the pushbutton works. Capacitive sensing may be used in any place where low to no force human touch sensing is desirable.

Features
On-board TTP224 capacitive touch sensor IC 4 keys
4 board-level status indicator
Working voltage: 2.4V - 5.5V
Advanced Pins breakout, so that the output mode and working mode selectable.
Low power selection
Size: 35mm x 29mm