Can somebody help with timer.

[newbie]

Need to make a timing system for my club.
We run the quater mile.
If the wires could be eliminated it would be better. If it needs wires thats cool also.

The idea is to have two pairs of photcells or Infrared transmiters for the two tracks.

Both at the start and the finish.
With a christmas tree to count down to green and to indicate false starts.

The time starts after the first beam is cut and stops when the beam at the end is cut. And the results displayed on a small screen.

Have access to a Pic Programer and facility to make cheap PCB's

Any help or guidance would be deeply appricated.

 

[Gene]

You are probably wondering why no one has responded. Well, you signed on as a newbie and your project is extremely complex. Do you have any experience with this sort of thing? Do you have a mentor at school? Do you have lots of time and $ for this size project?

I would start with the IR switching circuit. Just get it to trip when the beam is broken. Then work on a way to keep it from responding multiple times as different runners make/break the beam at the start. Next, you will need a similar circuit at the end of the track. They will need to be tied together to measure elapsed time.

Next would be the timer. It will need to be very accurate - probably to 3 or 4 decimal places. Do you have the knowledge/experience for this?

I would think that the tree starting system would be the easiest part of the project. Oh, don't forget that you wanted a false start indicator too.

Perhaps your track club could raise money to buy such an item...

 

[newbie]

Newbie as in new to this forum.
Can build allmost any circuit and follow most instructions.

Im allready looking at moding a PIC project to control trafic lights to work as the tree.

No formal education in Electronics but have done quite a few DIY projects.
Have access to a senior for guideance.

A typical system like this costs 1000s of $$. Way outside the resources of our club.

No issue on multiple cuts as there will only be two bikes runing.
Ive located something called a Pine Tree timer project thats very simple to build but it isnt exactlly what we need.

 

[bogdanfirst]

may i give and advice? mesuring the time and in a precise way will mean building a very complicated device. there are some electronic chrono clocks. you can use the signal generated by the circuits from the beams and some analog switches like 4016/4066 to connect the circuit to the chronometer. i thik that it is a better way to make the circuit that can mesure the time.