folk-qr

Hacked together in a couple of hours before QR Show.

Point a Folk gadget/system at a QR code, press the trigger button, and it'll scan and display the QR code decode result and render URL on the right half of the gadget display.

Decoding a QR code that just contains "Hello world!":

(video)

Viewing a URL (URL thanks to Owen, video thanks to Kelin):

(video)

No need for a phone, and people around you can see and participate in what you're doing too, they don't need to pull out their own individual phones to see what the QR code is.

Dependencies

Install the wkhtmltopdf package (we need wkhtmltoimage available).

Clone quirc into /home/folk/quirc and run make libquirc.so (you might need to remove the SDL env var definitions in the quirc makefile to get it to build.

License

Apache 2.0

Notes

• Doesn't require calibration or any AprilTags!

• Kind of hard-coded to the gadget: assumes 720p projection, Claim the button is pressed statement to trigger

  • On my Orange Pi 5 gadget, I have this in setup.folk to establish button state:

    exec gpio mode 7 up
    When the clock time is /t/ {
        set pressed [expr {![exec gpio read 7]}]
        Claim the button is [expr {$pressed ? "pressed" : "unpressed"}]
    }
    

• System freezes while doing URL download and rendering, would be good to do async and timeout (sometimes it freezes indefinitely if the page is too complex, which is scary and makes me paranoid when scanning untested URLs)

• (Unlike phone QR detect that runs continuously), for now only has one shot per button press to do QR detect. Often not reliable based on lighting/print quality/etc. Would be good to just keep retrying each frame until you get a QR code

• TODO: scan wifi qrs, scan program qrs

• replace qr code library with zbar or something OR improve stability of camera image? OR pre-binarize image (worked when done manually in imagemagick) before feeding to quirc