I'm not gonna do a full teardown yet, but you'll never guess what microcontroller is at the heart of this digital tape measure.

It's an ABOV MC96F6432Q.

which is an 8051!
Punch out another hole on your rewards card.

Rotary encoders are always beautiful.
The sacred geometry of electronics!

Is this a gray code, except for the innermost?

Or, no... Gray codes normally have their last row go like that eh? Interesting.

@rainwarrior @foone I believe the innermost row - combined with the next one - is a direction encoder. So you can tell which direction the thing is spinning by comparing the phases of the two.

@TomF @foone What I realized is that a quadrature direction encoder is also the upper 2 bits of a Gray code, so it's actually the same thing.

I don't have a great intuitive reason for why it "looks" like the pattern breaks in the last row, but thinking about every column needing 1 bit to flip: the "extra" flip in the top row fills in the gap where everything else has gone to 0 to fill out the sequence of 2^6 values.