Kind of off topic timing electronic type of thing.

[Drew]

I am running a motorsport event, and need timing gear.

Not a problem, until the cost of hiring said gear is £2000+.

So we had a plan. Surely it can't cost anything like that to build?

Soooooooooooo........

I thought 'Well, I don't really know where to start. Who'd know about this kind of stuff?'

Easy. TBCS.

If the collective knowledge isn't here, it isn't anywhere.

Here we go.

The timing is for a quarter mile drag and a sprint circuit.

I'm thinking lasers and recievers at the start and finish, hooked up to a laptop with a funky little program to run it and sort out the times (obviously, doubled up for the drag).

Oh, and a start light and win lane lights would be nice for the drag too.

Any ideas?

What I'm actually asking for is your collective knowledge to come forth and rescue me.

What I need is....

Some idea of where to get hold of the components (UK preferred).
Some idea of the names of the components.
Some idea of the cost of the components.
Anyone fancy knocking up a simple time recording program?
Is this at all practical?
Am I being a moron?

Help.......

Drew

[calumc]

i dont have a clue about programming but for hardware maybe you could do something with lasers and webcams?

[Crazy Buddhist]

i dont have a clue about programming but for hardware maybe you could do something with lasers and webcams?

Sounds like a combo-brothel-disco you're building :D

[Drew]

I was kinda thinking lasers and some kind of reciever... it might be raining, so it needs to be waterproof-ish...

And I don't wanna kill webcams willy nilly.

Thanks for the thought though.

[DaveW]

I could probably write the program for that, it's not complicated. But as for hardware, that's not a thing I have time for, same with drivers to interface with the hardware.

(To other hardcore geeks; I know there's some small problems with the above sentance, but just ignore them, ok?)

-Dave

[Crazy Buddhist]

Drew

You want IR beam technology my man ... and someone with a little electronics knowledge ... I think you are going to like this (http://www.easylinkuk.co.uk/page30.html):

PHOTO-ELECTRIC BEAM SENSORS - INFRARED BEAM ALARM
http://www.easylinkuk.co.uk/clipboard-045.jpg
(http://www.easylinkuk.co.uk/page30.html)
The FT25B is a two part infrared beam system. The infrared beam receiver is powered by 12V DC and is equipped with an output relay having N/O N/C contacts. The transmitter can be powered by either 12V DC or 2 x AA 3.6V Lithium batteries. Battery life is over two years. Installation is very quick and strait forward with easy beam alignment.

Some typical kits are detailed below.

ORDER CODE (BEAM SET ONLY) FT25B PRICE £54.00 + VAT

WOOT WOOT £54 smackers and you are well on your way to a fulll rig Or if you wanna get busy and mod them:

http://www.easylinkuk.co.uk/picture%20(png)-043.jpg
(http://www.easylinkuk.co.uk/page30.html)
BATTERY OPERATED PHOTOELECTRIC BEAM

Simple entrance monitoring device which creates an invisible beam across a doorway or area. Easy beam alignment with confirmation LED. Two beam distance settings. Low battery warning signal. Choice of alarm tones or single chime when the beam is broken. Both units operate from 1 x PP3 battery (supplied). Ideal for shop doorways, care of the elderly, children (when toddlers get on the move). Dimensions: 95mm x 70mm x 25mm. Beam range up to 10M.

ORDER CODE EL665 PRICE £25.49 + VAT

thats £50 + vat for both your start and end sensors ! (and they are in the UK) :)

I haven't looked for bargains this is the first stuff I found.

CrazyB

[Scotty]

You wouldn't want to use webcams if it's a racing event, slow things you'd miss them go by.
What about infared?
there has to be away of doing it with infared IR lights/LEDs are going to cost £2k

edit: Damn you CrazyB i knew i was right... you just posted a few minutes before :(

[D1337]

Youll save a TON of money, but it will be kinda ghetto rigged.

basically what youll be doing but the cam can be substitued for a laser
http://www.lildumpo.com/projects/autowoodchopper/


Lasers would work, and so would low quality camera's but they may be sightly off.

As far as programming goes, its pretty simple and straight forward. If you dont know anyone who can do it, you can hire a programmer online.

[DaveW]

I don't think InfraRed would be accurate enough...I think you'd need some lazers to get accurate readouts. In a drag race, those 0.01 seconds are gonna count.

-Dave

[Crazy Buddhist]

I don't think InfraRed would be accurate enough...I think you'd need some lazers to get accurate readouts. In a drag race, those 0.01 seconds are gonna count.

-Dave

As IR and lasers are both forms of EM wave and travel at similar speeds that make drag cars look like snails ... I think they are intechangeable in these circumstances? I can't see how it would make a difference.

CrazyB

[Crazy Buddhist]

WOOT WOOT GO TO YOUR LOCAL MAPLINS

£24.99: range of beam 100 feet !!!!!

http://www.maplin.co.uk/images/300/n76au.jpg
(http://www.maplin.co.uk/module.aspx?ModuleNo=37770&doy=14m8)

hhehehe

CrazyB

[Drew]

Thanks CB, that looks the part.

Now, if i go buy a bunch of these, how would I go about attaching them to the PC?

It says it flicks a switch.... now that could be helpful, cos it could be used to trip the win lights.

Would the reset be done via the software that was mentioned by Dave (gawd bless him, he's an angel)?

If so... it's just a case of getting the sensors working together and connected to the PC, let the programmer extrordinaire do his work and we're about there.

Connecting to the PC.... hmmmm. Now there I am deffo stumped.

Some kind of one off electrickery board thing that plugs into the serial port?

It needs to be able to send and recieve.... or does it?

I'm confusing myself now......

[Crazy Buddhist]

Thanks CB, that looks the part.

Now, if i go buy a bunch of these, how would I go about attaching them to the PC?

It says it flicks a switch.... now that could be helpful, cos it could be used to trip the win lights.

Would the reset be done via the software that was mentioned by Dave (gawd bless him, he's an angel)?

If so... it's just a case of getting the sensors working together and connected to the PC, let the programmer extrordinaire do his work and we're about there.

Connecting to the PC.... hmmmm. Now there I am deffo stumped.

Some kind of one off electrickery board thing that plugs into the serial port?

It needs to be able to send and recieve.... or does it?

I'm confusing myself now......

I'd do it with two laptops over a ethernet Cat6 or wireles N point to point (given the distances) network with recievers wired into the serial port maybe through a relay circuit of some kind? ... don't know what pins or how to access but I am sure you could do find out thru google.

Heres a drawing. Old-Schoolie-Paint-Stylee cos im on my soon to die XP Boot !

Matthew

ps those ^^ might only be online I didn't check.

http://www.freedomforall.net/Howto.jpg

pps You would need to make measurements of the lag to get your perfect timings.

ppps Also: Use your google-fu to find serial port switching/sensing kits/devices. I'd put your total cost on materials excluding assumedly borrowed Lappy's to be something in the range of £250 - £300 including two top notch wireless N devices. But I havent looked them up. Some really good Wireless G would do it but I'd spend the £ for the "power of N" lol.

pppps WOW: on weekends you can have a hobby you can enjoy: hiring out your kit for £2,000 a day hehehehehe

[dgrmkrp]

I've seem this done.. and you wouldn't guess where.. In a physics laboratory, back in high-school.. Some pupil made the electronics and the coding (visual c). His experiment was meant to measure the acceleration of a free falling object.. and he did have an option to time the pass between two points, by using IR laser diodes and receivers.. just like they used to have in ball mice.

So, instead of trying to fiddle around with networks and stuff like that, you could ask the physics teacher at your local school :)

I have an idea of myself tho: use 2 optoelectric circuits to first open a circuit to load a capacitor, then when the second circuit's beam is interrupted, another transistor (maybe using complemetary logic) blocks the capacitor out of the circuit. Done right and with some tweaking, u could determine the accurate time by measuring the stored voltage in the capacitor (this is how we determined the time 2 ball touch each other when they collide :) )..

hopefully this sparked some inspiration in someone :)

[Drew]

^^^^ fabulous comments guys.

But I'm an electronical n00b...... and Babelfish 'aint helpin.. any chance of a fairly simple explanation or solution?

I'm just realising how fik I really am.....

[Drew]

and he did have an option to time the pass between two points, by using IR laser diodes and receivers.. just like they used to have in ball mice.

And this one sounds particularly promising.

Except the bit about diodes and recievers used in ball mice... that seems weird to me.... IO thought they worked on a ball and rollers?

:edit: I'm a gimp. You mean the fan looking bit on the end of the rollers, don't ya?

D'oh......

[calumc]

if you can get access to 2 laptopsCB's option seems the easiest. all the software you need is built into windows!!
you just need to go run > cmd> ping [ip of other computer] and it will give you a readout straight away accurate to milliseconds and if you just subtract the normal ping time from it you have your time!

BTW i know that this is exactly what you were talkin about crazy but i jus thought id clarify it a bit

[Luke122]

Here's a company that builds these systems (http://portatree.com/splash) for you. They sell loads of different models, and some of the more basic ones might be fairly cheap.. but I havent found prices yet.

I'll keep on googlin' for ya. :D

[Crazy Buddhist]

So, instead of trying to fiddle around with networks and stuff like that, you could ask the physics teacher at your local school :)
:)


dgr Er .. I double majored in Mathematics and physics. Not sure where you are going but we're talking about doing this over a long distance at a drag race. Just as you calibrated your system so can this one be calibrated. It can be measured and doesn't leave mile long cabling for people to trip over.

It also has to pick up a car moving at ???? 100mph 150? more? I dunno ... And leave enough room betwen the IR source and sensor for the car to get thru ie the width of the track. That is a ready made sorce of kit fit for purpose for £100 for two sets. Building it yourself and being embarrassed when it fails on the day? I wouldn't.

Drew .. the kit from maplins, two serial port sensing kits (which will prolly come with sofware), two wireless N cards all mounted on sticks in the air connected to two lappys, that bit of software from Dave and your done

You said it yourself:

"Connecting to the PC.... hmmmm. Now there I am deffo stumped.
Some kind of one off electrickery board thing that plugs into the serial port?"

yepo thy searchercise time arriveth "google-fu!"

Matthew

[Crazy Buddhist]

Here's a company that builds these systems (http://portatree.com/splash) for you. They sell loads of different models, and some of the more basic ones might be fairly cheap.. but I havent found prices yet.

I'll keep on googlin' for ya. :D


I have - could still email for a quote on your system its ultra-simpler

ITEM DESCRIPTION .........#1............ #2......... #3
Total Estimated Amount $4,898.00 $6,560.00 $7,825.00 (http://portatree.com/media/images/banner/07-ElimQuarter.pdf)


3 kits thats a link to the pdf. ouch.

Try this for ideas:

"A phototransistor can be placed between Ground and Data Set Ready pins on
a serial port. An LED illuminates the phototransistor. When a car breaks
the beam, the computer notices (the line state changes). The computer is
running high resolution clocks (100 nanosecond resolution). You can place
a sensor at the start and end of the race, and have the computer do the timing.
Using the Carrier Detect and Clear To Send inputs along with the Data Set Ready
input, you can time three events per serial port. There are other input signals
available on serial lines, but not all systems allow you easy access to them." (http://scitoys.com/board/messages/1/179.html?1122186769)

Edit and to answer your next question:

http://techpubs.sgi.com/library/dynaweb_docs/linux/SGI_EndUser/books/SGIconsole_HW_CG/sgi_html/figures/pinout.O3000.console.port.gif (http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi/linux/bks/SGI_EndUser/books/SGIconsole_HW_CG/sgi_html/apb.html)

[Cool1Net6]

I'm just a budding CSE major, but I see 4 sets of IR sensors. The first 2 IR receivers are placed at the start, and are spaced from each other a few inches or so. These are used to line up cars evenly and accurately, and to make sure every race starts at the same location. The other 2 are placed at the finish line, 1/4 mile away from the start sensors, and spaced from each other similarly to the start line. All sensors are placed near the ground, and only "see" a car's tires.

When a car starts the race, the first beam is broken but the second is still in tact. You start timing as soon as the second beam is broken, and you stop timing as soon as one of the beams at the finish line is broken. I put 2 IR sensors down there to solve the "the cars move too fast" problem.

All of these sensors would hook into some computer system and as long as they all act as switches, I don't think it would be too difficult to program for them. If the sensors are quick enough, you could potentially use the 2 finishing sensors to calculate ending speed, but I am unsure of the accuracy.

And if your using WiFi N, you could always use some sort of cantenna to point your signal down to the start to help with signal strength.

My $0.02.

-Cool-

[Drew]

Right.

For experimentation purposes...

Shopping list:

Phototransistor or several (cos I will break one).
Serial plug terminal.
Bunch of wire.

Oh poo. I'll need some software.....

Stuff it, it's late, I'll think on it more in the morning.

Oh, and thanks guys. CB? You're a star. + reps all round for the help so far (and that left to come..).

[crenn]

My thoughts is to use a simple method... sort of.

You know how radar guns (the type police use to book you) measure speed by calculating distance over time? Using that principle except having the sensor being triggered when something comes closer than the set distance (aka starting line) and then trigger a 'stopwatch'. It waits for the 2nd distance (finishing line) to be reached and stops the stop watch. Using that, you can also measure the acceleration, average speed etc.

Just a rough idea.

[Xpirate]

This depends on how inexpensive the event is going to be. Official ET slips at a drag race give you your reaction time, 60 feet time, 1/8 mile time, 1/4 mile time, trap speed, etc. If you need to provide all this, the $ spend might be worth it depending on how much $ the event will generate.

If the event will just measure the time from when the light turns green to the time the lazer beam is broken at the end, you'd only need one computer that controls the tree lights and reads the lazer beam at the end of the track. You would also need some lazer beams to stage the cars as well. All they would need to do is activate the staging lights.

[Drew]

If the event will just measure the time from when the light turns green to the time the lazer beam is broken at the end, you'd only need one computer that controls the tree lights and reads the lazer beam at the end of the track. You would also need some lazer beams to stage the cars as well. All they would need to do is activate the staging lights.

BINGO!

All we need is exactly that.

These events will never make me rich... thats why something cheaper must be found. Oh, and as it's quite informal.... stage lights may be a bit much.

I would happily sacrifice some ultimate accuracy for consistency, and print outs wont be necessary. We're not talking a £50,000 prize pot or 6 second cars.

In fact, stuff it, heres what it is... and why I've been less than over-active on the forums of late..... www.driftwest.co.uk ... my new baby. And yes, I know the paypal buttons are broke.

It's just a timing system that keeps people happy that on the same track a 15 second pass beats a 16 second pass by a 1 second margin. Make sense?

Here's what I'm thinking at the mo...

http://i175.photobucket.com/albums/w144/driftwest/drag.jpg

A = Computer (duhhhh).
B = Start lights (bulbs or LEDs, probably LEDs).
C = Laser/ infrared/ whatever reciever.
D = Laser/ infrared/ whatever emitter (battery powered for less wires?)

I'm thinking staging will be manual, with a line in the road and a marshall.

A button is pressed on the computer, which sets the start lights off on a pre-programmed sequence (something like yellow, next yellow, next yellow, green) and on green the computer starts timing.

When the car breaks the beam at the other end, the timer is stopped and the time recorded.

Then the system could perhaps be reset by another button press from the computer.


So I need.....

Loads of bulbs/ leds for the get ready/ go lights.
Connector to computer for lights.
Timing beams for the end .... end.
2 emitters & 2 recievers.
About 1400 miles of wire (is signal loss going to be an issue here?).
Some amazing DaveW stylee program to run it all.

Anyone spot any obvious flaws before I go spending monies I haven't got?

[Crazy Buddhist]

BINGO!

All we need is exactly that.

A = Computer (duhhhh).
B = Start lights (bulbs or LEDs, probably LEDs).
C = Laser/ infrared/ whatever reciever.
D = Laser/ infrared/ whatever emitter (battery powered for less wires?)

...

So I need.....

Loads of bulbs/ leds for the get ready/ go lights.
Connector to computer for lights.
Timing beams for the end .... end.
2 emitters & 2 recievers.
About 1400 miles of wire (is signal loss going to be an issue here?).
Some amazing DaveW stylee program to run it all.

Anyone spot any obvious flaws before I go spending monies I haven't got?


No flaws all looks good. Signal loss just means you'll need a higher power supply on the relayed circuits - thats one of the reasons I was suggesting a wireless Lappy link to transmit the stop signal.

You will need a serial port In/Out Controller/Relay board or something similar. You could make one. I have found one example in the UK for you that costs £65 constructed. It has 8 output channels through relays (one for each of the lights! - and offers you those extra channels for the bright ideas that are sure to flow) and 4 opto-isolated digital inputs (whatever the f that means). Maybe there are simpler cheaper versions with fewer channels but this doesnt seem bad:

http://www.quasarelectronics.com/images/3000/3108_internal.jpg (http://www.quasarelectronics.com/3108.htm)

It can be operated at the end of anything up to a 100 foot long serial cable offering you extra flexibility in installing your setup. It comes with software or allows addressing the port through command line etc etc very flexible.

Edit: Drew, I just had a long chat to their tech support guy. Opto-isolation just means the input signal is fed into an digital-optical relay chip that isolates the input circuits from the serial port meaning no blown up Lappy's. This board is spot on. You feed the IR sensor into a relay put a twelve volt battery on a wire that makes a circuit with the board and when the IR is triggered the serial port will register the event. You will need to check that there will be a distinguishable signal with 12V on a half mile loop of cable. The board happens to run off 12V too. So a bunch of car batteries can maybe power the whole setup.

You can use terminal emulator I think he said to control it so if you can launch and control that from your App Dave its all done and dusted - the control commands are sent with the board and the boards own software is downloadable from the seller for free. Otherwise working out how to address the serial port and board won't be that hard would be my guess.

Edit2 The other reason I had suggested using Lappy's to send the "PassFinish" signal was that loads of cable trapsed around is a health and safety issue.

Plus: The above boards output cicuits can control AC circuits up to 250V or DC circuits (didnt ask the max). this is perfect. A few bright 10mm LEDS behind each lens is going to make a very visable set of Lights for the start line. You will only need to run 3 - 12v through these lines and again that cuts the health and safety risk if none of your long cabling has a high voltage. The problem is that long cables lose more power at high Amp to Volt ratios than at high Voltage to Amp ratios. This is why long distance power cables are typically high-tension (i.e voltage) and carry a relatively smaller current at several thousand volts, transformered down for domestic supply at substations.

Matthew

[Drew]

Oh

My

God!

An entire bucket of thanks go in your direction CB.

Do you have a link for that box of magic?

[Drew]

quasarelectronics.com.....

What a n00b....

That place is geeek/ nerd heaven!

But I can't find the actual one pictured :(

Link please :D :D

:edit:

What a pillock.

I just clicked the pic.

Knobhead.

[Crazy Buddhist]

Link please :D :D

:edit:

What a pillock.

I just clicked the pic.


Grasshopper, you are learning well. Keep your eyes open.

CrazyB

[dgrmkrp]

reply
I'm back, had some ISP problems.. Seeing where this is going... well, it is good to know there are lots of pre built stuff that others have come up with.. Ain't I a noob.. A noob filled with imagination tho ;)

Also, CB, you are absolutely right... I didn't think about the distance at first.. Long cables... BAD. Still, the demo I saw was pretty accurate... Like 6 decimals accurate.

I am studying to become an engineer (electronics) and am far from it. But I think I have the right mentality: think, create, and go back to the drawing board... Repeat :) So, I thought about this and overcoming distances: one laser and one sensor installed at a right angle. Add 3 90 degrees mirror systems and point the light beam in a circular fashion, as far as you can. At the first interruption of the circuit (e.g. start, the capacitor starts loading). Then, after several seconds pass, the circuit is interrupted again at the finish and the capacitor is cut off. Measure the voltage and do some simple math and you get the time interval. Circuit could be really fast as it employs few parts (some logical gates and maybe a latch or two), so errors are reduced. Also, by using a separate calibration circuit, which uses a timing IC (e.g.:LM555) to give 2 pulses at a known time distance, you could extrapolate the law at which voltage rises and choose a suitable capacitor for the desired track and known car times. The voltage is fed to an Electronic Voltmeter and converted in an ADC by the known law in a number>> the time. I am not saying this should be built, but this is sort of what I meant the first time. No advanced math or physics (at least not here). Just an idea :)

Oh, the grasshopper thing applies to me too :) If I said something stupid (and someone noticed), I apologize and quickly hide in the corner, wearing a nice pointy hat :D

[crenn]

I think you're thinking slightly over the top in the end circuit. All you need is a photodiode which is the same wavelength as the laser. The photodiode will have a current flowing because of the light shown on it by the laser. Once the light is interrupted, the current drops so you can take the time from when that happens. Also you need to think a little, I believe drag strips have 2 lanes. so you're going to need to have a separate triggering system for each lane, which isn't too hard to implement.

Here's a link to help try to understand photodiodes:
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

If I remember correctly, photodiodes have a response time of a few nanoseconds.

[Xpirate]

I didn't think of this before, but you might need a couple more laser emitters. It will help you see if one of the racers jumped the gun and launched the car too early.

The tree lights work like this for what is called a competition tree:
3 yellow lights, one green light, and one red
To start the first yellow light turns on
0.5 second later the second one turns on
0.5 second later the third yellow one turns on
0.5 second later the green turns on and starts the race.
The red light comes on if the racer launched the car before the green light came on.

Good luck in setting this up, and let us know how it goes.

[Drew]

The plan was just for a very simple way of consistantly measuring how long it took 2 cars to get over the line... I wasn't even considering people jumping the lights or getting into stage.

I would like to thank each and every single person who has contributed to this thread for your help and patience at my n00bishness.

However..... this project is scuppered before it really got started.

The insurance company for the events has vetoed the use of timing equipment (boo hiss to them).

So it looks like it's unecessary.

Still, with any luck this thread may have given people something to think about, and a chance to show of their brainpower.

Once again I am soooo impressed with the combined cleverishness shown on TBCS.

Many thanks and plusreppiness to you all.

[calumc]

i just thought of the perfect solution: a stopwatch :p

[crenn]

i just thought of the perfect solution: a stopwatch :pThat produces the element of human error.