Module work is a great way to learn "hands on".
I have only scanned this thread but its pretty neat Stan.
I have an idea that might be of use to some prototypically operating minded guys with long trains, or just for fun. A car, or axle counter.
Even if you had 100 receivers at least one could be tapped to double as a counter too.
I worked on a few machines that used two "screens" of receivers to track small flying objects. Though tracking was done with matrix logic, it used a few hundred little boards similar to this one. One of the many LED planes, counted too, by an added opto isolation circuit.
Lenses, and reflectors can help focus an L.E.D. for greater distance, & greater accuracy. Covering the emitter(led) with shrink tube, like the receiver in the video had, can keep the emitter from effecting other receivers near it, that its not paired to.
For easy custom beam focus, Id look at small flashlights & laser pointer lenses.
Ken,
If you have had a fear of, or tendency to overheat things badly, put the board in a hobby vice along the edges, and with one hand, lightly hold each diode leg nearest the diode with a pair of stainless steel needle nose. Just touching is ok.
The pliers will act as a heat sink to protect components, and solder wont stick to stainless. You can often heat both legs at once, and just flip it out.
Do a few like this & once your used to it, you can pop them out quick.
Don't blow at solder holes to clear them. Solder can spatter back at your face
. Use "solder wick" or buy a "solder sucker"(pens are best) for when you have stubborn solder holes to clear. Adding more solder, then removing it again, is a trick for the really stubborn holes that wont clear.
My "idiots method" is to heat holding a board, then quickly bang the heal of my hand on the bench, letting gravity do its thing. (that way I burn my hand with a bit of spatter instead of my lips, or eyes
)
