He provides full instructions on how to mod the trainer and interface it with the Arduino and he also provides the appropriate Brain library (same used with Neurosky headsets and Mattel MindFlex) to interface with the latter.
He is able to retrieve and visualize the data produced by the trainer which include Connection quality, Attention, Meditation, Delta, Theta, Low Alpha, High Alpha, Low Beta, High Beta, Low Gamma and High Gamma.
Nice work demonstrating once again how feasible it has become to acquire EEG signals with low-cost commercial – toy devices! Next step would be to try some data classification and try to actually build a train model out of the signals!
All steps and software available here.