Users of the Neurosky EEG brainwave sensor devices will be glad to learn that there’s an Arduino library for reading data. “Brain is an Arduino Library for parsing data from Neurosky-based EEG headsets. Tested units include the Star Wars Force Trainer and Mattel MindFlex.
It’s designed to make it simple to send out an ASCII string of comma-separated values over serial, or to access processed brain wave information directly in your Arduino sketch. See the examples for code demonstrating each use case.”
Instructions for the hardware-end of this hack are available from FrontierNerds. The library code is posted on GitHub.