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 
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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.
Hi,
thanks for sharing your project.
Btw, what is an “AIM IR transmitter beacon”.
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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…
bbq:
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!