[Noisebridge-discuss] Two-way optical interface?

[Sai]

After playing go with y'all a few times at Toorcamp, I thought of an
idea for a modified go board - namely one that's 100% normally
constructed, except that it would have Things at the crosses.
(Potentially it could also have them at the centers of squares as
well, if you want to have a board that could be used for other games
too.)

The utility: you could have physical play-by-email/server games (with
the local player just playing stones as normal, and being prompted for
where to play opponents' moves; you could have useful teaching cues,
like highlighting dead groups; you could have entirely novel kinds of
games.

The Things would need to
a) output light of different colors, and
b) determine what color stone (if any) is on top of them

Ideally the output light should work as a kind of halo around a normal
stone; possibly one could use clear or clear-cored stones instead,
though I think that harms aesthetics.

I'm not sure how to make such a Thing, though (and really, making
hardware is not at all my area of expertise, so I'm just guessing here
in the first place). If it were output only, I think that LEDs or
fiber optic cable would be reasonable. But how do I test what stone is
on top of them, especially if we assume unaltered stones?

I can imagine that it may be possible to have the fiber optic go on a cycle:
1. transmit a burst of test light
2. receive the reflection, classify it to determine stone that's on top
3. transmit actual display light for humans (most of the time)

I'm not sure if this is actually possible or not though; I know
nothing about fiber optic hardware capability. Any suggestions?

- Sai