Racers Lap Timer
I need to set up a lap timer in my car. I'd like to run it through my carPC, rather than buying something like the Longacre lap timer. http://www.longacreracing.com/catalo...d=271&catid=10 I'd have to set up something like this http://www.longacreracing.com/catalo...d=861&catid=10 with an auto trigger, rather than a manual one. Anyone have any ideas on even where to start?
in R/C car racing there are transponders that go in the car and they have the main unit that all the cars run under hooked up to a laptop. I dont know really what kinda of setup they have but in your case you would mount the transponder outside over where the lap starts/stops and have the computer hooked up to the reciever.
As far as an automatic trigger, most systems have an infra-red transmitter on the side of the track or a loop embedded in the track. I tried it using a remote control kit (as in a car alarm style one) but it wasn't real accurate. Probably the easiest is the infra-red transmitter. You can make one out of a dolphin torch and some IR leds. There should be quite a bit of info on the net about making IR floodlights, which is the same thing.
You then need a receiver in the car and then have it trigger your data pins in your serial or parallel port. Then all you need is to count the time between the pulses. You could probably write a crude app in VB to do this for you.
Note: Some track officials can get quite funny about timing yourself at trackdays. Been there and done that.
Hope this helps