This capacitive keypad uses the MPR121 proximity capacitive touch sensor controller and 12 touch-sensitive pads to give you a simple 'keypad' with an I2C output. The board also has four mounting holes allowing it to be used as an input system in place of traditional buttons. Check the example code below for an easy way to read the keypad.
A solder jumper on the back allows you to change the I2C address (set to 0x5A by default).
Note: This keypad uses 3.3V logic. If you are using a board which only accepts 5V logic, you will run into a problem. You will want to use a logic-level converter, or a board that accepts 3.3V logic.