thinking about the nintendo e-reader again, was curious how much data I could fit on a playing card. current trial is 2 kB of lorem ipsum as a type-40 QR code.
my phone can read this at 150 dpi (about 30 mm wide) if I use the camera app and switch to close-up mode, or 75 dpi (60 mm) in normal camera mode. A playing card is 69 mm wide, so I can just barely fit that. I guess nintendo's camera had the benefit of being designed specifically to scan teeny tiny 5mm wide strips, whereas my phone's camera is trying to focus on stuff at least a few inches away.
of course, my phone can see in grayscale, and even color, which means I'm not taking full advantage of that two inches. but I only have a black and white printer, and I couldn't find anything denser in black and white -- if you know a code that might work, let me know. But for now it looks like 2 kB in 60x60mm is the limit.
#barcode #programming #qr_code #gba