View Full Version : Stop gep while waiting for core

2005.07.30, 08:33 PM
I have always hated the antenna flag timing systems but couldn't wait for the core system. So with a little help from the google I came up with the Hot Slot Racing (http://www.hoslotcarracing.com/LapCounter.html)
The site lists the wiring diagram for game port, serial port, or parallel port and the software is fine for my use. All told I spent about $40.00 (couldn't find cheap laser pointers handy)

2 laser pointers $15.99 ea
2 Infrared Phototransistors (radioshack pn# 276-145) $1.59 ea
1 25 pin male crimp-style d-sub connector $1.89
1 2 ft section of 4" PVC $3.98
1 ethernet cable (had an extra)

The reason the laser pointer were so expensive is I bought the larger variety that run on AAA instead of watch batteries. Otherwise I could have cut my cost in half
All told assembly took about 45 minutes. The latency project web site had a really good how to on this that is still available on the web somewhere. He did a much more advanced laser alignment than I did. I basically eyeballed it and then used shims to adjust. Seeing as how it was just kind of a quick implementation I only set it for 2 lanes. Given more time and more attention to detail a more elegant solution allowing more lanes would be possible. All in all though well worth the time and money.