If you have modern WiFi router, there is a good chance you can enable a "Guest WiFi" network; that is, a network that can be used by guests to connect to the internet, but NOT browse other machines on the same network. It's very nice to set this up for your visitors.

And when someone wants to connect to your Guest WiFi network, they can either type in the password by hand, or on most phones, they can simply scan a QR code.  This placard helps you create a scannable code with all the information on it. I attached an adhesive magnet to this and have it on my fridge.

You will need to customize this for your own network, but it's pretty easy. The prerequisites are:

• OpenSCAD: https://openscad.org/

• xypwn's "scadqr" library, which does all the heavy lifting: https://github.com/xypwn/scadqr

No external dependencies, no "upload your wifi password to some sketchy online QR code generator that may or may not save your info"; everything happens in pure .scad language locally on your own computer. Simply edit the top of the wifi_placard.scad file and output to .stl. If you're new to OpenSCAD, here's a pretty good intro: https://blog.prusa3d.com/practical-problem-programming-objects-3d-printing-openscad_8415/ 

That may seem kind of scary, but if you figured out how to use Prusa Slicer, you can figure out how to you OpenSCAD.

Note that if you do a make of this, you should consider if you really want to post a photo.

Printing/slicing notes

• The QR code is pretty robust to minor printing "glitches". The QR section can be a bit of a stringing torture test for your printer, so make sure your filament is dry and that you have picked a good temperature for your filament so it resists stringing.

• I sized the text as small as I could while still having it remain readable. I used a 0.4mm nozzle, but a smaller nozzle would result in sharper text.

• Layer change at 1.2mm

• Note that getting text sized "just right" is a little tricky, so if you have a long password, it might slop over the edges until you adjust things. I tried to make it easy for you to adjust font sizes until they look correct.

Good luck, and I'd love to hear from you if you print this!

AI was used in the creation of this model

I wanted to see how good Claude was at creating models using OpenSCAD, so I asked it to create the initial .scad file. It was surprisingly efficient, although it had real problems getting the text into the right places. But that's kind of hard to do if you can't see the results, so it's understandable. In the end, I, am human, did read and finesse all of Claude's output. And unlike most "AI assisted models", I have actually printed and used the resulting model and QR code.