Specifications:

• Operating Voltage: 2V-5.5V
• Startup Calibration Delay: 0.5 Sec
• Simple to Use, Auto Calibration
• Output Status Indicator LED
• Output can configured be Active High or Low
• Output Mode can be configured to Toggle or Momentary
• Output can be directly connected to Microcontroller's Input pins

Product Description
 

To connect it with Arduino, connect Pins VCC and GND to power up the module. Connect the Output pins to any Digital I/O pins of the Microcontroller Board. Whenever the user touches the pad the corresponding LED will light up and the pin will go High. You can read this signal by using DigitalRead command. 
 

Additional Resources

Arduino TTP224 Sensor Module Project