The TTP229 Touch Senor Module employs TTP229 Capacitive Touch Sensing IC to sense the human touch and give the output accordingly. Unlike Mechanical and Membrane type switches, this offers touch-sensitive buttons and better workability and durability. The keypad offers a digital output of the first 8 keys and I2C output if you want to read all 16 keys of the touch module. I2C requires just 2 connections and can be directly connected to Arduino/ Raspberry Pi/NodeMcu, ESP8266, ESP32, etc. Since it is a very popular product, you can directly use it with above mentioned controllers without worrying about writing the libraries and low-level code. It can be used in a wide range of consumer products and as a durable replacement of Mechanical keys.
 
SPECIFICATIONS:
Operating voltage 2.4V to 5.5V
Built-in Voltage regulator
Stand-by current at 3V: 0.25uA at 8 Hz Sampling Rate
Two different operating modes: independent 8 Channel O/P and I2C interface 16 Key Mode
2 wires I2C interface for both 16 key and 8 key mode
Onboard LEDs to indicate which pad is being touched
2 Wires serial interface can select active high or low by option
Provides two kinds of sampling rate: slow sampling rate 8Hz and fast sampling rate 64Hz
Optional maximum key-on time about 80sec
Auto calibration at power-up (keypad must not be touched for 0.5 seconds after power-up)