4 ms·

Is that considered a 2D code? The height is fixed, but there are four height variations.

• myself248 4y ago
  It's almost exactly like the old magnetic Wiegand Wire swipe-cards, which align the wires high or low so they go past different read heads. I've always thought of Wiegand as a 1-d barcode because the displaced wires are just a way of achieving "contrast" and clocking, basically. But I could see the argument breaking down into semantics.