I had a MPR121 in my tool box. After getting my Raspberry Pi 2 installed with Windows IoT Core, I wanted to get this MPR121 Capacitive touch break out board working with it. While Adafruit had a library for Arduino, there wasn’t an MPR121 Driver for Windows IoT Core readily available. So I wrote this Windows.IoT.Core.HWInterfaces.MPR121 library in C# that can be used with the Raspberry Pi. In addition to the sample app available in the Github repo, I also created a Touch sensitive Christmas tree using this library. This post describes a few things about the MPR121 library.