The Puff and Suck (or Sip and Puff) systems allow people with minimal or no mobility to interact more easily with computers using a straw-like unit as an input device. [Ana] tells us that the usual way these devices are used to enter text involves a screen-based keyboard; a cursor is moved to a letter using a method (joystick, mouse emulator, buttons or eye tracking) and that letter is selected with a sip or puff in a tube.[Ana] I have seen such systems as effective and intuitive to use, but also limited in speed because there is only so fast that one can select letters one at a time. This led to trying a new method; one that requires a little more work from the user, but the reward is the insertion of faster text. The Puff-Suck interface for fast text input turns a plastic hollow disc and a rubber diaphragm into the bipolar pressure switch, which can detect three states: suck, blow and idle. The unit works with a pair of emitter and IR receiver on each side of a diaphragm (half of which is shown in the image above). When the air is drawn in or sucked out of the unit, the diaphragm moves and physically locks one or the other emitter-receiver pair. The resulting signals are interpreted by an attached Arduino.
How does this allow faster text input? Launch the usual "keyboard-to-screen" interface and use Morse code, with puffs like dots and suck like dashes. The project therefore acts as a sort of keyboard with Morse code. Requires skill from the user, but the reward is much faster. The idea was selected as a finalist in the Hackaday Prize 2018 Human-Computer Interface Challenge section!
The Morse code may seem like a strange return to someone, but not just the bipolar nature of [Ana]The bellows switch looks a lot like that of the Morse code input pads, it's also easy to learn. The Morse code is all but dead; we have pages of projects and news that show his involvement in everything, from extravagant projects to the resolution of serious communication needs.