The 3DS Streaming Console with External Control Interface, or 3xtDS, is a modified Nintendo 3DS console equipped with an capture card and an USB interface that allows the control of buttons, circle pad, and touch screen from an external source, as well as streaming high quality video of the content of both screen and sound back to the host to be recorded, or broadcast. This allows some very interesting applications such as interactive streaming on Twitch or other websites, gameplay automation, remote play over Internet, using alternative controllers, and much more.
Please see a short video of it in action: https://www.youtube.com/watch?v=9PZrJH7Z8KE
I want to thank u/velocikoopa for providing a console for me to work on, without him this project would be impossible.
Project gallery: http://imgur.com/a/ICxh5