TTP224 is a capacitive touch IC, you can convert your PCB into a touch Pad ! well this is useful if you want to replace a traditional Button , or you want to add a touch feature to your project.
TTP224 comes in a common breakout like in the picture, very cheap and so easy to integrate in your project.
with this breakout , you have 4 output pin (OUT1 - OUT4) , and normally the output is 0V "LOW" ,and once you touch the pad the signal rise to VCC "High".
The voltage supply VCC can be from 2.4V-5.5V so it's compatible with all Arduino boards 3.3V/5V .
In this tutorial I will show you how to use this breakout with some applications like :
Let's start with the components: