> Instead of a rotary encoder to measure the tape rotation, it now uses an IR led and sensor.
I don't get it; how does this work? Are there openings at certain positions in the reel that it detects the light through? Why is this better than the rotary encoder design?
> Are there openings at certain positions in the reel
Yes, that's exactly it! The spool has holes, and there's an IR emitter/detector on either side. You can view the STLs on the GitHub repo or Printables and see for yourself.
It's better than the rotary encoder [for this project specifically] because it's cheaper and doesn't require the sensor to be a load-bearing part.
> Instead of a rotary encoder to measure the tape rotation, it now uses an IR led and sensor.
I don't get it; how does this work? Are there openings at certain positions in the reel that it detects the light through? Why is this better than the rotary encoder design?