50 Lines is an interactive conceptual art installation by Kevin McVey.
Its purpose is to showcase and celebrate the subtle beauty of simple geometric patterns. Try it out here.
Though the piece can be run in one's browser, its proper presentation is in the form of a physical installation. There are thus two versions of this code, one for the Web and one to be run on a Raspberry Pi. Please see the project's homepage for more. (also pictures!)
50 Lines is run as a web application in a Chromium kiosk window. This version, however, has been modified to operate using keyboard input in place of a GUI.
For installation purposes, this keyboard can also be replaced with physical pushbuttons tied to the Raspberry Pi's GPIO. This code (located in /RasPi/Keyboard) requires WiringPi and is thus built using the -lwiringPi gcc flag. A pinout to keyboard to action diagram is below:
WiringPi : Keyboard : Action
-------------------------------------
0 : H : Horizontal box
1 : V : Vertical box
2 : F : Forward diagonal box
3 : B : Backward diagonal box
4 : N : Blank ("null") box
5 : , : New line
6 : <left> : Move cursor left
11 : <right> : Move cursor right
8 : <bksp> : Backspace
9 : C : Reset to default
10 : P : Print (or debug)
Note that the pins above are WiringPi pins, and do not match the pin numbers used on the Raspberry Pi itself.
A custom autostart script is also provided here in the event that your installation is intended to boot straight into this software. Simply modify the file locations on lines 4 & 5, and then place the file in your Pi's /etc/xdg/lxsession/LXDE-pi/autostart directory.
Enter combinations of H, V, F, B, N, and comma into the control box on the bottom of the page. Share with friends by simply copy/pasting your automatically updating URL. Yep, it's that easy!