[gjh1000]

Hello all,

I am a Slot car racer, and I am building a lap counter for home use for my GCSE electronics project. To help me with researching this project, I would like some info on what the most important aspects are, so if any of you can spare a minute to help, I would appreciate it greatly.
Please number the following aspects 1-12 in order of importance:

1. Ease of portability
2. Ability to count up to set number of race laps and then switch over to count down mode for the race
3. Size/compactness
4. Sound at the end of the race to signal the race is finished
5. To be mains powered
6. To be battery powered
7. Should the counter be a box at the side of the track
8. Should the counter be a bridge type over the track
9. Should the counter be mechanical and then be fixed to the underside of the track
10. Should an Infra Red non-contact sensor be used
11. Should individual lap times be recorded
12. Should the best lap time only be recorded

Please answer and feel free to add any general comments as well.
Thanks!

 

[Slots-O-Fun]

I think it would be interesting to develop a system that shows intermediate times at various places around the track as well as a single lap time. This would give you information such as who is fastest down a straight or through a set of "esses" or who is fastest on the first and second half of a track for example.

 

[RichG]

Too much emphasis on potential solutions & not enough on understanding and defining the key requirement for a lap counting /timing system.

Which is to 100% reliably detect cars. Once you can do that with no missed or wrongly attributed laps, everything else is a piece of cake, or a bit of software.

Rich

 

[2FER SLOTS]

You are working on a good thing

I agree with the above!

Accurate #1
Portable #2 (no computer needed or laptop etc)
Adaptable#3 (1 lane track or expandable to 8? lanes)
Info #4 last lap,best lap,average speed....anything else you can think of LOL
Simple #5 flip a switch,push a button and race !
Power #6 most tracks are close to outlets aren't they? Batteries always go dead when ya need 'em.

I wish you the best sir.

 

[nameci]

Hi!

I see you want to do in standalone mode. what type of microcontroller would like to use?

I am working on a lap counter for a long time (it will end someday, I hope

) ... in my case I use an Arduino which gives me the following:

portable
Possibility of using batteries
Small and compact
Easy to program

... and much more that might be interesting for your development.

You can see it:

http://iceslot.sytes.net/category/slot/marcador/

or

http://iceslot.sytes.net/category/slot/marcador/?lang=en
(with automatic translation)

 

[speedyroadster]

I would agree with RichG, 100% accurate detection of a car passing the start/finish line is the most important point.

In my latest project (for a single lane rally track) I've used a 741 Op amp to compare the resistance in two LDRs mounted in the side of a bridge. One LDR is placed low down (where a car would cover it) and the other is placed well above nowhere near the car or track. On the other side of the bridge are two high powered white LEDs shining directly at the LDRs. When a car passes, the Op amp compares the difference and sends a signal to the output (this is where you need to think about the counting part of the project and what you need - I suggest you ask your Electronics teacher what is available). Some companies are able to supply complete counting kits as electronic projects for schools. I'm pretty sure but the exam board won't be expecting something to rival the best Scaley/Ninco/SCX can offer so don't over complicate it!

Good luck

Alan

 

[300SLR]

Hi gjh1000
Do you just want to produce a lap counter, or do you aim to produce something the run races?

I'm don't know how much time you have to develop a system for a GCSE electronics project - maybe to attempt more than just counting laps is too ambitious?

If you want something to run races you should consider how to start and stop races.
Starting would normally be done by turning the power on (a dead start) OR
By telling the drivers when to start (either by lights or sound) and having some sort of jump start detector (a live start)

Stopping races is normally done by turning the power off when the race distance (normally a fixed number of laps or fixed length of time) is completed.

Looking quickly down the list
I agree with RichG - counting laps accurately is essential.

Type of detector - anything that works (dead section / split tape / light beam across the slot / light bridge over the slot / magnetic etc. are OK, don't care if the light beams are visible light or IR, but avoid mechanical detectors too much risk of interfering with the car)

Best of luck with the project

Mains power is fine.

It's not essential to record lap times. If you do only the fastest needs to be displayed but preferably all should be recorded and retrievable after the race.

 

[gjh1000]

Thanks for help everyone!

Just to clarify, I am making a Lap counter with NO timer (couldn't find constant manufacturer of the chips I wanted). I have designed a circuit (which works!), where the user sets the number of laps, then flicks a switch (rocker) before they start the race. I can't do a start sequence unfortunately without adding loads of components. I have made sure that each lap counted will only count as one lap by using a schmitt trigger to eliminate switch bounce. The design of the case is a bridge over the track with an infra red sender and receiver, which sends a signal which is broken by the car.

Thanks!

 

[Lasp]

Today we got wery cheap and easy to handle small computers. Arduino is one whery good example. And the new RaspBerry will change the way of thinking in getting time and all another information.
Please keep program simple, possibelitys too run different typ av races.
All information about earlyer race and my inventory of cars could bee in a separate program.
But It must be accurat, easy realible and quti cheep!

 

[AAWSCC]

i would try and keep it to being built into the track. Having just built a track I had to make sure the lap start/finish was positioned in building. I used a LDR with led above. It would have been much nicer to be able to place it anywhere.

 

[-Sy-]

Arduino is good, the initial cost is low, however if you want to make it do anything serious, then the add ons can make it expensive....I've been playing with one for several weeks...good points IDE is free, buggy but free...downside no online debugging facilities...I've now gone back to PIC microcontrollers, they are cheap, well featured and there are lots to choose from. I bought the easypic 7 dev. Board and IDE for c from mikroelectronica...good price and a lovely development system, with full debugging support.

Timing depends on Pic chosen and crystal...you can easily time to millisecond resolution and higher.