SlotForum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter · #1 ·
Hi,
What's the best way to detect a Carrera D132 car as it passes over a section of track? I was thinking about using a Reed switch or a photo cell detector. If I go with the photo cell, any suggestions on which one to buy?
I will be using this to control lighting along the track via a PC.
Thanks,
Harold
 

·
Registered
Joined
·
577 Posts
QUOTE (hkfears @ 17 Jun 2011, 13:41) <{POST_SNAPBACK}>I will be using this to control lighting along the track via a PC.

Hi Harold

Sounds like an interesting project - I "assume" that this is to turn track lights on and off?

To your original question - I have no idea but will follow this to see what you come up with.

Cheers
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #3 ·
I have an older PC with a parallel port, which will be used to control the running of the light.

I believe I will go with 4 Reed switches (2 per lane). Reed switches are magnetic switches that are typically open. When a car passes over it, they will close. In theory, if a program monitors the status of the 4 circuits, it should be able to control the light.

Harold
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #4 ·
Today, I have the software detecting the cars and flashing yellow caution lights around a couple of corners. The Reed switches are very sensitive and are able to pick up the magnets in the engine and magnets used to help control the car.

I was planning to have the PC blink yellow LEDs (as a warning light) as a car passes thru a section of track. However, it was soon apparrent that it is just as simple to just flash them for a given amount of time (0.75 seconds) after entering a section. Using one parallel port, I can monitor 4 points of interest and blink 4 pairs of LEDs.

Note that with a standard parallel port, one should be able to monitor 9 locations without too much difficulty.

Other applications could include playing sounds, such as crowd noise as a car passes the grand stands.

Any other ideas?

Harold
 

·
Registered
Joined
·
3,057 Posts
Interesting development. I am considering using reed switches to run some pit lane lights and find your progress very informative.

Please keep us informed.

Cheers!
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #6 ·
The parallel port's status register consists of 5 bits that can be easily monitored. To do this you will need two Reed switches and use 2 of these bits. You can simply run the wires from the port's pin to the switch and place them at the desired location. The magnets used to hold the car to the track and the magnets in the engine will close the switches.

What would the pit lights do? How many LED's would it take?

Harold
 

·
Registered
Joined
·
3,057 Posts
Any updates?
Curious to see what you chose in the way of reed switches as there are many sizes and ratings out there.
I did find on another forum that SCX in-car reed switches are about 14mm x 2.54 mm (46 mm with wires) rated at 1A and 15W switching power.

Cheers!
 

·
Premium Member
Joined
·
923 Posts
A few supportive points...

Each parallel card has eight bits you can use. They are not perfectly easy to handle, which you have noticed if you use all of those five one usually get to at first.
And there is accommodation for three such cards in the standard PC.
On top of that there is the usual eight bits going out (to the printer head).

So with a most ordinary computer you could handle 24 trigger points.
But remember, if you want anything near correct timing you have to get the old MS-DOS operating system and that with no "multitasking" types, like Windows, anywhere near that hard disk.

I would be careful depending on magnetic reed switches if using the motors for triggering. Direction, placement and strength make for a very unreliable way to trigger.

The possibly best way, if you only want to catch that a car, any car, is passing is to use an IR-barrier stretching across the track itself.
Remember that you could probably supply the power needed directly from the, digital, track.

Installing an IR-barrier inside the slot itself is not as easy as it sounds. You quite literally need to cut a whole right through the surface to get it far enough up to actually catch a passing guide flag.

Anyhow, good luck!
It is always nice to see projects adding to the hobby!
 

·
Registered
Joined
·
3,057 Posts
Is there a simple way to detect the guide in the slot? I know awallace has separated the guide detection from the LED detdction for his SSDC rms program.

Cheers!
 
1 - 9 of 9 Posts
Top