The QR keychain encodes a link. The WiFi plate encodes a network. Point a phone camera at it and it offers to join the WiFi, no password typing, no reading letters off a router sticker. Handy for a guest room, an Airbnb, or a cafe counter.
Two things make it work: a small text payload that phones recognise as “join this network”, and a code that still scans once it is a printed plastic plate.
A string that means “join this network”
iOS and Android both understand one little format inside a QR code: WIFI:T:WPA;S:NetworkName;P:password;;. The T is the security type (WPA covers WPA2 and WPA3, or WEP, or nopass for an open network), S is the network name, P is the password. The QR is just that text.
The one part that quietly breaks is punctuation. If the network name or password contains a semicolon, a colon, a comma, a quote or a backslash, each one has to be escaped with a backslash, or the phone reads the string wrong and the join fails. So the payload builder (wifiPayload) lives in its own small, tested function, because a password like a;b:c is exactly the input that looks fine and silently doesn’t connect.
A code over a caption
The plate is a QR on top with a few lines of text under it: a title, the network name, the password if you want it shown, and a “Scan to connect” line. The builder reuses the QR generator from the QR keychain and the line-by-line text layout from the sign plate, then stacks the code above the caption and sizes one rounded plate around the whole thing.
Printed codes have one rule the screen version doesn’t: keep it dark on light, with a clear border. The modules print as raised dark plastic on a light plate, and there is a quiet margin around the code so a camera can find its edges. That is also why the colour pickers default to a black code on a white plate, with a note not to invert them.
Show the password? Your call
There is a toggle for printing the password in plain text under the network name. The QR already contains it, so this is not about secrecy, it is about the guest whose old phone won’t scan, or who wants to type it into a laptop. For a guest network that is fine. For your own home network you might leave it off. Off by default, on with one click.
Office WiFi is a different animal
This plate is for the home-style networks with one shared password (WPA/WPA2/WPA3). Company networks that log you in with your own work account (the 802.1X / enterprise kind) are not something a QR can reliably auto-join. Phone cameras just don’t act on that.
So an office version is its own product, coming next. It won’t pretend to be one-tap. It will show the network name, the sign-in steps, and a link to your setup page, which is the honest version of “get the team online”.
Make one
Type your network name and password, pick your colours, and the QR builds as you go. Print it, stand it on the counter, and guests are online in a tap. If you want a custom product like this in your own shop, that is what disip builds.