PaulRB:
Can you post a picture/link to that? Your description does not sound right. See the forum guidelines to find out how to post pictures and links.Not sure how well the PIR sensor will work for starting the race. Another ir beam break sensor may be better.
Sorry about that, it's the 7 segment LCD display Green 7-segment clock display - 0.56 digit height : ID 813 : $3.95 : Adafruit Industries, Unique & fun DIY electronics and kits
I think I'll order another of the IR break beam sensors instead of using the motion sensor... I actually found a link for a hot wheels track set up that will work identical to my idea, but instead of a track that fits a hot wheel car, it will fit a human! The concept is simple, sensor at start, it starts the stopwatch, then sensor at the end, and it stops the stopwatch.