SplitSecond Hardware Description

I recommend using photocells for several reasons.

1. They are easy to find. 
2. They are solid state--no moving parts.
3. They will work with any cars.

Here is a parts list of what you will need to make an interface. 
All of these can be found at Radio Shack, or other similar stores.

Cadmium-Sulfide Photocells (RS# 276-1657)
An old parallel or printer cable 
--OR--
25-pin male parallel connector and some small-gauge wire.
Solder and soldering iron

The pins used for SplitSecond are 12, 13 and 18. 
Connect one of the leads on two photocells by twisting them together. 
Solder the wire from pin #18 to this lead; solder 12 and 13 to each 
of the other leads.

If you are using a scrapped cable, I recommend using continuity 
tester or a multimeter to track down the wires you want.

        Male Side View
  1 ------->              13
 _____________________________
 \ . . . . . . . . . . . . . /
  \ . . . . . . . . . . . . /
   -------------------------
   14 ----->             25 
 


12------\
         \
          O - photocell
         /
18------<
         \
          O - photocell
         /
13------/


That's really all there is to it. To install in your track, carefully 
drill a 1/4" hole between the slot and the rail. This hole will have 
to be elongated slightly to accommodate the oval shaped photocells. 
Take your time. It can be a tight fit; it may be easier to remove 
some of the plastic around the rail first. You can secure the cells 
with some glue if you wish.

Then use option 6 on the main menu to check that everything is working
Properly. Write down the different values you read for both covered, 
lane 1 covered, and lane 2 covered. If you don't get any change in 
values make sure you have enough light on the cells. I have an 
overhead fluorescent that provides plenty of light for my layout. 
Also check your parallel port address.

Chris Moellering
moellering@fwi.com
January 12, 2000