Locked-in Syndrome Users can now blink type, for under $10

Blink-based Aural Scanning Keyboard with Morse Code option

Using a simple template matching technique, this Processing-based app makes it possible to type text using blinks only. The app distinguishes 3 types of eye patterns that are registered at initialization: normal, action, extra-action (corresponding, typically, to a normal eye gaze, eye rolled-up, and eye shut). Currently only two gestures are used.

An earlier version uses webcam, and is demonstrated here:

The latest version uses closely mounted USB borescope that looks at the eye.

The user is prompted aurally with the row number (row of letters) and, on blink ("action" pattern), then individual letters within that row.

Row 5 is used for additional letters/functions (see Manual).

Optionally, the user may enter into Morse mode where she could blink the letters using Morse Code convention. To get back to normal aural scanning mode, a 6-dot blink should be used.

The entered text is stored in a buffer of 20 lines. The current line is automatically stored when it is more than a number of letters (the last being a 'space' letter). The stored lines maybe pulled back (last-in first-out) into the current line for editing.

The app has option for sounding a bell.


  1. You need the Processing environment
  2. Within Processing, add the following libraries: OpenCV, minim

It is also possible to get a pre-compiled version for OSX and Windows 64.

Menu layout

The menu interface is maintained in code/menu.json. The behaviour of the app could be entirely changed by re-designing menu.json.

Future developments

Interface with a browser and email programs.


The code works well but needs refactoring to be more easily maintained. Some actions, for instance switching from Morse to scanning mode, maybe slightly delayed.

Use under MIT license. The code writer assumes no liability for the program's use.

(C) Ability Spectrum, 2015-2016.