Project Black Mirror is an effort to activate and use Apple's Siri using thoughts alone (see How Smart Is Siri? for more information on Siri).
(Project Black Mirror Thought-Controlled iPhone video)
The technology behind Project Black Mirror, like many popular DIY hacks, centers around an Arduino microcontroller chip. EEG pads attached to the skin transfer brain activity to the Arduino, which is responsible for filtering the signals and associating patterns with certain words and Siri commands. The words are combined into phrases to form a complete Siri command, and the entire command phrase is fed to a speech synthesizer chip which audibly recites the command through the iPhone 4S’s microphone jack.
SF greats Jerry Pournelle and Larry Niven made use of a similar idea in their 1981 novel Oath of Fealty. In the novel, a communications implant allowed individual users to communicate with a powerful mainframe computer with only their thoughts, bypassing the computer's sophisticated spoken-language interface:
"I used my implant to tell MILLIE what we wanted and she took care of it," Art said.
"I see," Sir George's eyes focused on nothing for a moment.
Art said "Mac, have they made any progress on swinging an implant for you?"
"Think the city's got an extra million bucks?"
Sir George said sympathetically "Very useful gadget, but you can communicate with a computer about as well with a good briefcase console." Reed and Bonner looked knowingly at each other. It was a look that sighted men might give each other in the presence of the blind.
(Read more about Pournelle and Niven's communications implant)