QR-code generator: wifi, vCard, URL or text (parametric, cadquery)

Install build123d (a cadquery evolution): 
https://build123d.readthedocs.io/en/latest/installation.html 

Install the Python segno QR code generator and image library:
conda install -c conda-forge segno
conda install -c conda-forge imageio

Error correction codes from low to high: L,M,Q,H
The QR-code version is automatically calculated to the quantity of data.

The pixel-dots are scaled to an integer number of extrusion widths. Extrusion width is typically between 1.1 and 1.2 times nozzle size. Prusa slicer uses a value of 1.125 by default.

The image filename is embossed on the bottom of the base.

The functions allow you to set a QR code image scale value, but all this does is to scale up the png image pixel count, no new information is added. It is best to leave scale=1 and control the size of the print by setting ndots (the number of printer dots per one block).

The Python script file has examples of all the variations.

The png file images are all very low resolution (one print dot per pixel) and display poorly in this website because of interpolated size upscale, but even these poor images work surprisingly well!  You can even scan the Prusaslicer screen grab. Try it!

The examples in the Python script are:

• A fictitious wifi code. Remember that anyone with access to the wifi QR code image can read the password! 
• A simple text block “Welcome to our home!”
• A Google Maps URL link to the Chartres Cathedral.
• A URL to this page.
• A URL to a video on YouTube - the classic “Dear Mr Fantasy” interpreted by CSNY.
• A contact card in the MeCard format.
• A contact card in the vCard format.

When printing, select one of these two options:
1. do all layers in white and then blacken the pixels with a permanent marker.
2. print the base in white and the top few pixel layers in black.

References:

https://segno.readthedocs.io 
https://www.freecodecamp.org/news/how-to-create-stunning-qr-codes-with-python
https://en.wikipedia.org/wiki/QR_code 
https://help.prusa3d.com/article/creating-profiles-for-different-nozzles_127540 
https://filament2print.com/gb/blog/150_basic-laminating-parameters.html 
https://the3dprinterbee.com/3d-printer-line-extrusion-width/ 
https://3dprinterly.com/how-to-get-the-perfect-layer-height-setting/