Mental Block reads the users Alpha and Beta waves. It translates the Alpha waves to illumination on the wearer's face. The more mentally present, the brighter the wearer's face. Beta waves are translated to the rotation of a polarized filter disk. If both wearers' beta waves are on the same frequency, they can see each other clearly. The more the wearers' mental states differ from each other, the more obfuscated users' faces become from each other.
We started off by building three headsets, the system was designed to scale to any number of users, growing the number of potential connections quadratically. Communication between brain-reading headset wearers becomes more and less direct based on the relative alignment of their brainwaves.
To gain access to human brainwaves we hacked Star Wars Force Trainers produced by Uncle Milton Toys. The headset portion of the toy contained a chip made by NeuroSky which takes in transcutaneous electrical signals from the brain and turns it into serial data. The Force Trainer transmits the serial data over bluetooth to a base station, which when used in the "proper" way maps the values to the speed of a fan and thus the height of a ball. Our online research only took us so far. We found a diagram outlining the header pins on the bluetooth receiver within the Force Trainer base station, but could not coax serial values. Emails to the hackers we fruitless. To get around this issue we tapped the Tx, Rx, power and ground pins on the NeuroSky chip itself, with positive results-- we got a steady stream of 32 data packets from the Tx pin, and the Rx pin proved to be useless. (It was about here that we must have fried the NeuroSky chip because for a while we thought the sensors were dubious, giving us poor connectivity denying us the packets we had fought for). Fortunately, NeuroSky wants people to do strange and wonderful things with their chips and published the content of the packets with good documentation. The data from the Tx pin went into the Arduino. We wrote a parser in Processing and made a graph to illustrate the aforementioned brain states of "attention" and "meditation,". The next hurdle was sending the data wirelessly to the computer. We used Xbee Series 2 radios to send the data directly into a digital pin on the Arduino, which processed the data, and spat it back out through its own TX pin to the Xbee, and then wirelessly to the computer. The idea was that once the central computer received steady streams of brain state data from all three headsets, the data could be used to control various outputs.
There are a few applications we wanted to go with: a performative application, a meditative one and a fun, user-oriented one. This links to the other implementations are Just Between You and Me and Brain Radio.