IR Lap Timer

Development Boards MicroMod
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Hi,

thanks for sharing your project.

Btw, what is an “AIM IR transmitter beacon”. :o

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JimEli:

mcuaust:
Hi,

thanks for sharing your project.

Btw, what is an “AIM IR transmitter beacon”. :o

For the timer to work, an IR Transmitter Beacon is required to define the start/finish line. There are several commercially made systems that utilize beacons, such as AIM, Hotlap, Traqmate, etc. Most of these beacons are encoded so the timing and associated data acquisition systems can distinguish between each other. My timer piggybacks off the AIM beacon.

http://www.aimsports.com/

What’s really entertaining is to watch 10 people setup their AIM beacons / transmitters next to each other on the track. Everyone’s timers trigger off the first beacon and ignore the rest…

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nice project :slight_smile: I’ve just started at looking at making something myself for racing. Have you got any more details of whats in the box and the tic tac box? Would be a great help!

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I have an AIM Beacon transmitter and a Mychron headset, would your receiver work on this, if so what board do you have connected to the PNA4602M inside the tic-tac box to make it operate the headset.

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Wow, this is just what I was looking for. Something affordable. A couple quick questions though. Have you made any progress with adding more transponders? I am not sure what is generally out at the trackdays I attend, likely XT or AIM so I am probably ok. Secondly, do you have a schematic for the circuit(I have never played with Arduino stuff so not sure if it is as simple as it sounds from your description). Lastly does the timer have memory(i.e. 10 laps or something), you may have mentioned it but I didn’t see any reference. Have you had a chance to do any more testing with it other than in your neighborhood?

Thanks!

Kevin

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JimEli:
I am happy to report version 2.0 works great.

It’s a simple IR reciever/interface module that activates an external chronograph (I used a DRC SP1 motocross lap timer–google it).

The module involves a pna4602M IR detector, AVR ATtiny85 and associated circuitry for power (9v battery).

Accuracy was within a 100th of a second as compared to the AMB track timing equipment. The SP1 has lap memory capability and costs about $50.

Details can be found here:

[aTtiny85 code using arduino timing code

[schematic

I have 8 express-pcb boards for the project if anyone is interested.[/quote]

Thanks for keeping us updated, the schematic link does not work though. I am sure what you mean by “express-pcb” boards, are these just etched boards ready for populating with the components? If so I would likely be interested depending on the cost of the other required parts.

Thanks,

Kevin](http://home.earthlink.net/~jameseli/Misc/IRLTv2.PDF)](http://home.earthlink.net/~jameseli/Misc/irlt.c)

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JimEli:
sorry, the link works now.

Yes, I made a batch of pcb, and have bare boards left over. I think the parts could be sourced for under $10. Add for an enclosure, wiring, bells-whistles, etc. You would need an AVR programmer too, and that would allow you to modify the code to suit your whims.

Contact me offline if interested in a pcb.

I still intend to add more timer codes too…

Ok yep the schematic works now. I think I have most of the parts kicking around except the AVR and IR detector. I have a couple questions about the schematic though. What are CV, CG, IS, IV and IG. I am assuming they are inputs and outputs for the IR Detector and timing device.

I am probably interested in a PCB from you, I didn’t see your email address but here is mine. crippler75@gmail.com so you can let me know the details.

EDIT, would this programmer http://www.sparkfun.com/commerce/produc … ucts_id=33 work ok? Or is there a cheaper/better alternative you recommend?

Thanks,

Kevin

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Do you know what frequency the AIM beacon modulates at? I believe the carrier is 38KHz but it is a pulsed signal at a lower frequency? I have seen this to be ~5mS with other beacons…just wondering if you are detecting this pulse to validate the signal or just an “edge”…i’m worried direct sunlight would give a false trigger.

Do you have issues with direct sunlight and your PNA4602M or is that what the tic-tac box is for?

I’m going to try a pre-wired TV IR receiver that has a tinted lens and i’ll post how this works.

I’d love to hear how your transmitter is coming along.

Thanks!

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Hi Jim,

I just bought a racecar fitted with an AIM Laptrigger. So - no money left, need to build my own beacon :smiley:

I just took the sequence you measured and hacked into an arduino. Despite just having a red LED for testing, it worked in a dry run. It should be noted that the PNA4602M inverts the signal, i.e. you need to send IR-pulses during the periods you measured as low.

Need to buy some IR-leds and test it on the track though. Thanks anyway for sharing the info!

Cheers,

Andy

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