Inexpensive Lap Counter?

[lnx_author]

OK... did some googling this p.m....

where are the inexpensive lap counters?

all i've seen is Tomy's overhead (about US$18) but no good screenshots...

looks like project time!

[latency]

Now, this page has some info for making your own lap counting system with some laser pointers, photo receivers, and a pc. Basically it works off the premise of multiple lasers going across the track at different heights. When a car goes thru, you have little flags at different heights on the cars antenna. Each laser trips when the flag goes thru at that designated height, and records the lap times etc...

He does not go into a ton of detail, but it is still a good read nonetheless.

http://www.itsallbutstraw.com/Mini-z...ap_Counter.htm

Then there is this guy who is selling one already built for about $380.... Very high, but I am getting a Mini-Z soon, and I have talked to my local hobby shop, and we may build one for their track....

http://www.mgsweb.com/rc/lapcounter/forsale/Index.html

[lnx_author]

US$380???!!!!

whoa!

i found a parts list and bare schematics for one using about $25 in Rat Shack parts, but no detailed connections, P/S requirements or perf-board/PCB layout...

this one is going to have to take some thought... one of the Tomy's i looked at required the car to physically pass through a gate (which could be a challenge, i guess)...

what i'm looking for i just a simple counter - don't need a PC interface... a number of open source designs are available using a 1284 port (LPT) ...

maybe a simple reed relay and mechanical counter might work; perhaps one could be designed without the need for a battery... ideally it would be cheap, easy to be put together, simple to set up, simple to reset, yet still provide a large enough display of lap numbers...

or perhaps just a series of flags, with one flag dropping for each completed lap?