Here is a video of an XBox ChatPad on my Raspberry Pi. As they both work on 3V3 and UART, they wire together without any additional electronics. I did add two resistors as a precaution on the data lines.
The driver however took a bit of work, the Broadcom datasheet has a lot of typos in it.
I will post the full details of how to build it in a few days time when I have had time to write them.