Quote Originally Posted by Snap View Post
Yes the projector is for the rest of the racers to see. It will display the real time race times and laps for each lane.
What I mean is...the spectators aren't going to be able to see the difference between updates every 1/100 of a second or 1/10 of a second anyways, so why not slow the updates down a bit. Let the PIC keep track of actual times down to whatever resolution you want, but only send them to the PC every 1/4 second or so.

I need to time 2 cars and need a way of manually stopping the timers when there is a crash.
Is the timer stopper also going to cut power to the track? (I'm assuming these are the powered type slot cars)

If the pic and serial port can handle a real time 1/100th second update I will use it for timing if not I will only use it to start the windows timer.
With the way Windows software and PC hardware is set up these days, an input from a PC's serial port would probably be buffered in some fashion, and due to Windows multi-tasking capabilities, quite possibly might not get acted upon for a number of milli-seconds (or seconds on a slow machine ). Therefore, I think the best way to do it would be to keep track of absolute time at the track with a PIC, and send off those elapsed times/lap times/etc to the PC once in awhile...whatever the PIC/PC combo can handle. But again, I wouldn't think it would have to be that fast. After all, wouldn't people be watching the actual race, and not a big ol' TV screen?