Re: Barcodes & error detection

> First, there is slight variation in the barcodes themselves that may
> negate this (light sensor inclined 2 degrees to the west will still be
> perpendicular if a section of the barcode is inclined 2 degrees to the west;
> rare, yes, but the error rate is already only 3%). 
I had in mind a steeper angle - let's say 20-30°. Light sensor optics is very
primitive!!!


> Second and more critically,
> to distinguish all three "colors" (white, black, and highly reflective) (...)
>    Using retroreflective white tape (...) would seem to work, but actual tests show that it often
> can't be distinguished from white.

Serious objection... From my laser sensor experience, I tend to think that
retroreflective tape would work well, but maybe not enough to separate from
white. Experiment needed!

Rob's suggestion about ambient light shielding is very wise too...

Philo