QR Encoder

Encode ASCII string to a Version-1 QR code of this ASCII-art format, where all the v and ^ must be filled with "#" and spaces.

    #######  vv^^ #######
    #     #  vv^^ #     #
    # ### # #vv^^ # ### #
    # ### #  vv^^ # ### #
    # ### #  vv^^ # ### #
    #     #  vv^^ #     #
    ####### # # # #######
            #vv^^
    ### #####vv^^##   #
    vv^^vv ^^vv^^vv^^vv^^
    vv^^vv#^^vv^^vv^^vv^^
    vv^^vv ^^vv^^vv^^vv^^
    vv^^vv#^^vv^^vv^^vv^^
            #vv^^vv^^vv^^
    ####### #vv^^vv^^vv^^
    #     # #vv^^vv^^vv^^
    # ### # #vv^^vv^^vv^^
    # ### #  vv^^vv^^vv^^
    # ### # #vv^^vv^^vv^^
    #     # #vv^^vv^^vv^^
    ####### #vv^^vv^^vv^^

The 10 vertical "strips" of ^^ or vv must be written from right to left. The bits in a strip are written in a zig-zag order: ^^ zig-zags upwards, and vv zig-zags downwards. The bit on the right always precedes the one on its left.

    ^^ ..    vv 10
    ^^ 98    vv 32
    ^^ 76    vv 54
    ^^ 54    vv 76
    ^^ 32    vv 98
    ^^ 10    vv ..

The strips are filled with data from a bitstream:

    0100  00010001  01001000  01100101  ...  01101111  0000  11000000  11111111  ...  11101110
    Enc   Length    'H'       'e'                 'o'  End   c0        ff             ee
    (4)   (17)      (17-byte ASCII message)            (0)   (7 error correction bytes)

To encode a bit from the bitstream to a strip, determine the coordinates (x, y) of the current position in the bitmap with the origin (0, 0) at the top-left corner, invert the bit if (x+y)%2 = 0, and write the value to this position ("#" = 1, space = 0).

External links: Wikipedia