Micropython module for producing QR codes (written in C)

This code is using the fine library from https://github.com/nayuki/QR-Code-generator written by @nayuki and published under MIT license.

• almost able to be compiled into a native-code .mpy file, but not quite
• does not support Kanji or ECI modes

MicroPython v1.12-483-g22806ed5d on 2020-06-08; darwin version Use Ctrl-D to exit, Ctrl-E for paste mode >>> import uqr >>> help(uqr) object <module 'uqr'> is of type module __name__ -- uqr ECC_LOW -- 0 ECC_MEDIUM -- 1 ECC_QUARTILE -- 2 ECC_HIGH -- 3 Mode_NUMERIC -- 1 Mode_ALPHANUMERIC -- 2 Mode_BYTE -- 4 VERSION_MIN -- 1 VERSION_MAX -- 40 make -- <class 'RenderedQR'> >>> q = uqr.make('abc123') >>> print(q) ############## ###### ############## ## ## ## #### ## ## ## ###### ## ## #### ## ###### ## ## ###### ## ## ## ###### ## ## ###### ## #### ## ###### ## ## ## ###### ## ## ############## ## ## ## ############## ## ####  ###### ## #### ###### ###### ## ## ## ## ###### ## ## ## ## ###### #### ## ##  ########## ###### #### ############  ## ########## ## ## ##  ## ## ## ## ## ## ############## ###### ###### ## ##  ## ## ######## ## ## ## ## ###### ## #### ## ## ##  ## ###### ## ## ## ## ## ##  ## ###### ## #### ## ## ####  ## ## #### ###### ##  ############## ## #### ## ## ##  >>> q.width() 21 >>> q.version() 1 >>> q.get(3,3) True >>> q.packed() (24, 21, b'\xfe\xe3\xf8\x82\xb2\x08\xba\xb2\xe8\xba"\xe8\xba2\xe8\x82\xe2\x08\xfe\xab\xf8\x00\x98\x00:\xc78\x90W(K\x8c\x90\xf9\xdb\xf0\x13\xea\x80\x00\xa5(\xfewP\x82x\xa8\xba\xc1P\xba\xa4\xa0\xba\xc9`\x82c\xa0\xfeMP') >>> # (width, height, packed binary b/w data) [padded to byte boundaries on each line]  >>> help(q) object ... is of type RenderedQR __del__ -- <function> width -- <function> get -- <function> packed -- <function> version -- <function>

Create a QR code:

urq.make(message, min_version=1, max_version=10, encoding=0, mask=-1, ecl=uqr.Ecc_LOW) 

where:

• message: Binary or text to be put into the QR code. Can be bytes or unicode string.
• encoding: Default is auto detect, but you can force encoding to be bytes, alphanumeric (ie. 0—9A—Z $%*+-./:") or numeric (0—9).
• mask: default is -1 for auto select best mask, otherwise a number from 0..7
• min_version: minimum QR version code (ie. size)
• max_version: maximum QR version code. size). Supports up to 40, but default is lower to conserve memory in typical cases.
• ecl: error correcting level. If it can use a better error correcting level, without making the QR larger (version) it will always do that, so best to leave as LOW.

Returns a RenderedQR object, with these methods:

• __str__ renders as a QR code (mostly for fun)
• width() return number of pixels in the QR code (be sure to add some whitespace around that)
• version() returns the version number (1..40) that was used
• get(x, y) return pixel value at that location.
• packed() returns a 3-tuple with (width, height, pixel_data). Pixel data is 8-bit packed, and padded so that each row is byte-aligned. The padding is at the right side of the image and will be: 0 < (width-height) < 8

• Using invalid parameters, such as asking for lower case to be encoded in alphanumeric will raise a RuntimeError with the line number of qrcodegen.c where you hit the assertion.
• To control the QR version number and therefore fix it's graphic size, set max and min version to the same number.