The MPR121 is a capacitive touch sensor controller that is controlled via I2C interface. Conductive surfaces can be used as capacitive touchpads and controlled via the module. The chip can control up to twelve separate electrodes, plus a simulated thirteenth electrode. The MPR121 also has 8 LED driver pins. If these pins are not configured as electrodes, they can be used to drive LEDs. Features - Operating voltage:1.71 ... 3.6 V DC - Operating temperature: -40 ... +85 °C - Dimensions (LxW): 31 x 20 mm 2 matching pin headers included in the scope of delivery