Help with creating a timing system for race track

[jc1ortiz]

Hello everyone,

I am attempting to build a hot wheels race track for my kids and I am having trouble finding a good timing system for it. What I would like to do is have a sensor at the starting line that start a clock and one at the finish line that stops the clock and sends the results to two LED displays at the end of the track. FYI I am not very good with programming any type of controller but I will try if need be. Can anyone give me any advice as what direction I should take. All suggestions are welcome...


Thanks...

 

[SABorn]

The simplest micro controller to use is the Picaxe chip, i would consider using a LCD display as it is easier to write to than a LED display as the picaxe can interface direct to a LCD but you need a driver for the LED displays.

As for the code to do the timing it is rather straight forward as all you need is some form of a start signal, that could be a simple light beam across the track and then just run a counter loop in the picaxe program something like...

Main:

Pause 10

inc counter

if counter = 100 then
inc seconds
counter = 0
endif

if seconds = 60 then
inc minutes
seconds = 0
endif

goto main

>>>>>>>>>>

Then its just a matter of adding in the start and finish triggers and a display routine.

In the above program loop "pause 10" stops the program for 10 milliseconds so you will get a timing period of minutes , seconds, and 1/100 of a second.
Inc means increase by 1 (or add 1 to counter, etc.)

All very easy and im sure once you start you will find many other projects for the picaxe chip.

Pete.

 

[Boncuk]

Hi jc1ortiz,

if you don't like to dig into microcontrollers here is a timer circuit using discretes.

For a one-second-time base you might salvage a crystal operated clock (kitchen clock) and use the output signal adapting the signal level for CMOS logic level using a switching transistor.

The image shows the circuit at a count of 104 seconds.

To start and stop the clock you might use a simple light barrier with latching output.

Boncuk