Lap Timer

[Steve]

Originally posted by wild03
Steve, looking around the software I noticed that it has a "Track Power" feature, (F10) It allows you to toggle pin2 +5V on and off
This will allow for a relay to toggle power to the track on and off...
I'm thinking I can power the laser with this pin, Then I can control the laser with the PC and everything ends up in one neat package...save you another $15 on the power supply.

It also has support for a "Track Call Switch" but I have no idea of what this is used on slot car racing.

Ooohhhh! be sure to tell us how you did it if it works. Careful though, wouldn't want to toast the I/O board in your PC.

[wild03]

Originally posted by Steve
Ooohhhh! be sure to tell us how you did it if it works. Careful though, wouldn't want to toast the I/O board in your PC.

Now I'm confused
I found a page on the net about parallel ports and they say the output is around 24 milliamps, I E-mailed the software author(gregory replies to my questions in a couple of hours, great guy, free custumer service for a free product doesn't get any better than this....) and he replied that the port produces a couple of hundred milliamps plenty to power a small 5VDC coil relay! If it can do the relay It should handle the laser with no problem.

What we need is an expert opinion here..

Anyways It's a good excuse to fire up one of those pentium 1s I have in the closet as a guinea pig...YOu are right steve one wrong move and there goes the paralel port!! Smoke it's kool

[Steve]

I'm assuming you are using this with a PC, so just run a lead out of your box...you should be able to find an extra 5v plug floating around in there.

[wild03]

Originally posted by Steve
I'm assuming you are using this with a PC, so just run a lead out of your box...you should be able to find an extra 5v plug floating around in there.

I was thinking about that one, Even taking some the the Parallel cable wires that are not being used to carry the voltage to the rig. This will work nice with the old Pentium1 I'm planning to use because I can TAP into the parallel port wires inside the PC itself since they are in a ribbon cable, THis will be harder to do with the new ATX mobos that have the port comming out of the board.
I will have to put a big WARNING label on the port cuz if someone plugs anything else there! ZAAPPP!!!

Well I'm pretty much convinced that the port will only handdle less than 30mA maybe 24mA, I took an amp reading of the laser diode and it's 32mA, SO I build a relay driving circuit so I could control up to 4 lasers. The circuit I found here.

http://www.hut.fi/Misc/Electronics/c...el_output.html

The little 5V relay I found requires less than 10mA to activate so the port circuit should be happy. The relay will be controlling 4.5 volts and up to 130mA if I use all 4 lasers. I wired the lasers in parallel. I tested the circuit using external power and it switches just fine. The next step is to try it on the PC once I reinstall 98 on the pentium1.
I'll also build a adjustable voltage regulator to drop whatever outside power, ( PC or transformer) to the 4.5volts the lasers require.

I'll keep posting updates but it seems like it's gonna work!

[Steve]

Nice work! What you gonna do with 4 lasers though?

[wild03]

Originally posted by Steve
Nice work! What you gonna do with 4 lasers though?

DAmn!! that's a good question! Since the software can handle 4 channels I didn't think about it and started building for 4 channels
Heheh!!!
Well since we don't have an easy way to run all 4 channels on circuit races, the most practical application will be for drag races, and setup one channel per lane using your mirror trick, or for performance testing by setting up all 4 channels on one lane one after the other, one channel from 0 to 3 feet, the other from 3 to 6...etc. that way the timing for each segment can be recorded in one run to provide info on acceleration and top speed at different segments of the track! Thats a lot of mirrors BTW

Anyways, I did the parallel port rig, Used pin 16 and 18 to carry 5 volts to the box. For the 5v I used the power cable that went to the CPU speed LEDs on the Case. (don' see those anymore )

I ran the rig on the Pentium1 PC, All is ok! IT turns the 4 channels on and off by pressing "F10".
The only thing left to do is a small voltage regulator circuit to fit inside the box to drop the 5v to 4.5v - 4v for the lasers.

I'll have pictures soon!

[Steve]

I've seen packages of small 1" mirror pieces at craft stores...they're pretty cheap.

I've been wanting to build a drag strip with several speed traps. Let me know if you get that far.

can i ask a stupid question please

well really its like stupid advice :-P wat i was gonna say is could u use a lazer pen for your beam thingy... radio active x gamma ray antidisestablishmentarionism HA! stick those words in your book of mega confusing stuff!!!

[Steve]

Originally posted by Bit Char Bloke
can i ask a stupid question please

well really its like stupid advice :-P wat i was gonna say is could u use a lazer pen for your beam thingy... radio active x gamma ray antidisestablishmentarionism HA! stick those words in your book of mega confusing stuff!!!

um..what?

dorry dont ask.. i just had sum ribena ( makes me hyper )


anyway....... wat i was saying was for your IR beam lazor thingy could you use something out of a lazor pen, if you could you wouldnt have a problem with range

also do you no when you go race 1/10 scale rc's they give u a little chip to put in your car for the laps, cant u get a tiny 1 of them for a bit?

and what has your exellent work i must say got that the tomy IR lap timer hasnt. im just curious thats all

thanx

[wild03]

Originally posted by Bit Char Bloke
also do you no when you go race 1/10 scale rc's they give u a little chip to put in your car for the laps, cant u get a tiny 1 of them for a bit?

and what has your exellent work i must say got that the tomy IR lap timer hasnt. im just curious thats all

thanx

If you could get those little chips, you could used them but I imagine the complete system costing some serious money!

The tomy lap timer is $20 you can get the same results using a pc for $6 tops!!!

I'm just enhancing my timer to use all 4 channels and to do linear time so that puts me at about $20 in parts.

wat i was saying was for your IR beam lazor thingy could you use something out of a lazor pen,

Well yes, but laser pens are expensive compared to the $3 keychain laser pointers I have.

[Steve]

Well, at the time, I didn't know about the Tomy Bit Lap Counter, so I built my own using a laser pointer and a laptop PC. Since then, I've learned of the Tomy unit, but with the PC you get a lot more power and flexability. For instance, because the PC has memory, you can store different car setups, testing sessions, fastest laps, practice results, race results, average lap speed, and so on. The home built unit also covers a lane anywhere from 1 inch to pretty much a mile in width.

As for transponders, they need batteries, which means weight, and there isn't much room in a bit for xtra anything, let alone a transponder. The smallest one's I've seen are about the size of a Bit anyway. I wish it were different as our problems would be solved.

Finally, building my own was fun, I've never done anything like that before.

[wild03]

Originally posted by Steve
Finally, building my own was fun, I've never done anything like that before.

True THAT!!!
I finally finish my timer rig, here are some pictures, for a little more detail visit the page




All works great!!! All left to do is to put this baby to work and finally get some times!

more details at:
http://www.geocities.com/wdiaz03/laptimer.html

[Steve]

Nice instructions. That cassette tape project box is classic!