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QR CODE MAKING: BIGGER IS SMALLER

WHEN YOU MAKE QR CODES, CAPITAL LETTERS MEAN SMALLER QR CODE AND OTHER NOTES ON MAKING THEM.

That is a neat trick from Terence Eden’s blog where the cause is also explained.

Automaattinen sisällysluettelo / Automatically generated Table of Contents

• qrencode
• WiFi QR codes
  • iwd Device Provisioning Protocol
• Other methods of generating QR codes
• QR code readers
  • See also

qrencode

qrencode is my favourite method of creating QR codes, with the above fact a small QR pointing to my website would be:

• qrencode -t utf8 -i https://aminda.eu
  • -t utf8 outputs to terminal as unicode and -i ignores case turning input UPPERCASE.

However my former goto was:

• qrencode -l H -t utf8 https://aminda.eu which would feature higher error correction allowing more damage (including art) while still working.

Storage:

• qrencode -i -s 6 -l H -o aminda.eu https://aminda.eu
  • This -s 6 doubles the pixel size, -l H uses highest error correction and -o aminda.eu outputs the image to aminda.eu.png. This could be converted through magick aminda.eu.png aminda.eu.jpg

However usually I end up to qr.bash.

WiFi QR codes

For details on the specification, please refer to Barcode Contents on zxing wiki instead.

• Open network with SSID openwireless.org_nomap: qrencode -t utf8 "WIFI:T:nopass;S:openwireless.org_nomap;;" (wifiqr-open.bash)
• WPAX protected network with SSID Hollow and key Bastion: qrencode -t utf8 "WIFI:T:WPA;S:Hollow;P:Bastion;H:false;" (wifiqr.bash)
• Hidden networks? Change the H:false to H:true.

iwd Device Provisioning Protocol

If you are using iwd for WiFi management, forget the above and to add a new dpp capable device onto your network, instead iwctl dpp wlan0 start-configurator which requires qrencode.

To stop provisioning new devices iwctl dpp wlan0 stop.

Obviously don’t include the dots and replace wlan0 with your actual interface.

Other methods of generating QR codes

• DuckDuckGo search beginning with qrcode
• Firefox add-on: Offline QR Code Generator
  • This has spared me headache countless times on school computers for getting URL stored to my browser from school computers or virtual machines without complicated setups.
• Chrome Web Store: QR Code
• BinaryEye & SecUSo for Android below

QR code readers

• The stock Camera app.
  • At least on iOS and SailfishOS.
• BinaryEye is my go-to app for QR codes and will tell you more than you might want to know about them. Google Play, F-Droid
• SecUSo: Privacy Friendly QR Code Scanner for Android , Google Play, F-Droid

See also

• Mikaela/gist directory vcard