This is a 4X4 16 Key Capacitive Touch Keypad. Unlike mechanical and membrane keypads, this offers touch sensitive buttons and better feel during usage. Having no mechanical components, this keypad offers better durability compared to other mechanical keypads. This keypad offers digital output for first 8 keys and I2C digital output if you want to read the state of all the 16 keys. I2C requires just 2 connections and can be directly connected to Arduino/ Raspberry Pi/NodeMcu, ESP8266, ESP32, etc. Since these keypads are very popular, guides, tutorials and libraries are available for Arduino, Raspberry Pi and other micro controller, which means you may directly use this keypad in your project without worrying about implementing the low level code. This helps even new and first time users reduce product development time when using these keypads. The TTP229 Touch IC is capacitive sensing design specifically for touch pad controls.The device built in regulator for touch sensor. Stable sensing method can cover diverse conditions. Human interfaces control panel links through non-conductive dielectric material. The main application is focused at replacing of the mechanical switch or button.This Module can replace conventional 4×4 keypad with a touch based keypad. The module has two working modes. A 8 key mode that provides a independent 8 channel output or a 16 key mode that can be used with the I2C interface of the module, there by saving even more pins and connections on the application Arduino or Microcontroller board. Features