The MPR121 capacitive keypad uses the MPR121 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. Project description, more information and ordering can be found at https://www.sparkfun.com/products/10250 Datasheet: http://www.sparkfun.com/datasheets/Components/MPR121.pdf Example Code: http://www.sparkfun.com/datasheets/Sensors/Capacitive/MPR121_Keypad_Example.zip Dimensional Drawing: http://sparkfun.com/datasheets/Sensors/Capacitive/MPR121-Cap-Touch-Keypad-v11_Dimensions.pdf