Creating a QR Code step by step

by D4Haon 11/17/2024, 6:26 PMwith 46 comments

by Timwion 11/18/2024, 12:57 AM

Unfortunately it seems that every online explanation of QR codes always leaves out the Reed-Solomon error code calculation. The author here describes it as “long, tedious, and not very interesting”, but since everyone seems to think that, it is now very hard to find.

by throw0101con 11/17/2024, 10:43 PM

Recent Veritasium video on the topic, "I used to hate QR codes. But they're actually genius":

* https://www.youtube.com/watch?v=w5ebcowAJD8

by belteron 11/17/2024, 6:36 PM

The feedback he receives is quite fun: https://www.nayuki.io/page/poor-feedback-from-readers

by bb88on 11/17/2024, 9:59 PM

This is pretty awesome. I would like to see the same thing for the decoder.

by greggman24on 11/18/2024, 12:53 AM

it's nice to have an explanation. for me, I just wanted to quickly make them. Googling led to ad covered sites and "register to use" site. Found a few on GitHub but they had other issues so threw together my own using a well designed library I'd used before. took about 15 minutes

https://greggman.github.io/qr-code/

might add more options but in truth I don't think most users need the options

by aabijion 11/18/2024, 3:37 AM

I built an implementation in Rust a while back:

https://github.com/aabiji/qr

by redbellon 11/17/2024, 8:50 PM

A good practice is to tag the title with the year of the article (in this case, 2018), when it is not from the current year.

by jazaon 11/17/2024, 10:38 PM

Nice! Learning how QR codes work has been on my todo list for ages, this was a nice introduction.

by fforfloon 11/18/2024, 4:31 AM

Plug: Now that you know how they work, you can use them in your SQL queries too https://github.com/Florents-Tselai/pgQR

by sligon 11/17/2024, 11:03 PM

This resource is awesome. I wanted to have the smallest readable QR code for my printables pages footer [1], and I discovered there that it's possible to encode URLs in "Alphanumeric mode", version 1, using only uppercase characters, e.g., HTTPS://FOO.CC/ABCDEFGHIJ, so I got a three letter domain name and built the simplest URL shortener hosted on a CF worker.

[1]: https://pdf.ahaprintables.com/pdf/preview/aha/zebra-puzzles-... (PDF)