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By JimEli
#102393
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Last edited by JimEli on Thu Jan 13, 2011 7:34 pm, edited 1 time in total.
By djk
#105609
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!
By JimEli
#105793
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Last edited by JimEli on Thu Jan 13, 2011 7:35 pm, edited 2 times in total.
By bbq
#105995
Hi Jim,

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

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
By JimEli
#106037
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Last edited by JimEli on Thu Jan 13, 2011 7:36 pm, edited 1 time in total.
By bbq
#106052
I ordered some Osram 4546 LEDs with about the same specs as yours, 20° beamwidth. I decided not to take a too narrow beam because the code sequence takes about 10ms and i'm not sure if the AIM triggers on partial codes as well. I'll plug in a ULN2803 as a driver and aim for 4 LEDs with 1A current each.

Should work, we'll see :D
By JimEli
#106053
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Last edited by JimEli on Thu Jan 13, 2011 7:35 pm, edited 1 time in total.
By bbq
#107028
Been on the track yesterday and tried my transmitter. It worked well initially, however rain and an uncharged car battery prevented a longer use.
Anyway, the Arduino with the ULN2803 driver circuit and 4 Osram 4546 LEDs performs very well. Total current consumption is about 150mA, each LED roughly 1A pulse current. I'm going to get a Li-Ion battery and build it into a nice box now.
Sourcecode for Arduino (Mega328, AVRStudio+WinAVR) on request.
By JimEli
#108121
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Last edited by JimEli on Thu Jan 13, 2011 7:35 pm, edited 1 time in total.
By MA$TER_E
#115668
Hi JimEli!

I did my first track day in September and I'm hooked. (sportbikes) I've got a list of things to buy one of them being a lap timer. Long story longer I started getting into this Arduino business and am making a gyro cam type of system to mount on the tail of my bike (as I lean the camera counters). And finally getting to the point I started thinking HEY! Why don't I make a lap timer? So here I am…

I was going to buy an XT Ultra-Lap Lap Timer with both the transmitter and download module which is going to run you around $300 bucks for the whole setup… Although their system is very refined and sophisticated I think I could get what I need better and cheaper using an Arduino.

The plan is to make a system very similar to yours except I'd like to add an SD card data logger so I can pull the txt files over to my laptop at the end of the day and import them into my own little analytical software. But in the future I'd like to look into what will be involved feeding in a whole bunch of sensor data for a full scale custom data accusation system (throttle position, RPM's, gear number, break pressure, tire temps and maybe even tire pressures)

Anyway, the thread has been inactive for a while and I wanted to see if there was any further development or discoveries made. How has it been working for you so far? Is it still working for you pretty good? How are the batteries holding up?

Eric

Build a man a fire and he's warm for a night...
Set a man on fire and he's warm for the rest of his life...
By jrfoell
#182556
bbq wrote:Been on the track yesterday and tried my transmitter. It worked well initially, however rain and an uncharged car battery prevented a longer use.
Anyway, the Arduino with the ULN2803 driver circuit and 4 Osram 4546 LEDs performs very well. Total current consumption is about 150mA, each LED roughly 1A pulse current. I'm going to get a Li-Ion battery and build it into a nice box now.
Sourcecode for Arduino (Mega328, AVRStudio+WinAVR) on request.
BBQ, I know this is a long-shot with this thread being so old, but I'm interested in the source code (and schematic) for your IR beacon. I have an XT Ultra Lap and I'd like to build a beacon for it. Thanks!