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jjv
01-14-2004, 11:18 AM
I know that FIRST has said that the IR beacons will both be at the same frequency, but different Pulse Widths. Has anyone seen anything that indicates what these will be?
I'd like to make a mock up of these for use in practices.

Kevin Watson
01-14-2004, 11:43 AM
I know that FIRST has said that the IR beacons will both be at the same frequency, but different Pulse Widths. Has anyone seen anything that indicates what these will be?
I'd like to make a mock up of these for use in practices.It's discussed in this thread (http://www.chiefdelphi.com/forums/showthread.php?t=23600&page=2&pp=15) and here's another one (http://www.chiefdelphi.com/forums/showthread.php?p=207964#post207964). I've posted an illustration of what the waveforms look like here (http://kevin.org/frc).

-Kevin

bfvaneyck
01-15-2004, 10:10 AM
Do we know the P/N for the IR emitters?

Random Dude
01-15-2004, 11:34 AM
Do we know the P/N for the IR emitters?


From the sheet that came with them (the one with the schematic) the P/N is EOD-EL-1L2

bfvaneyck
01-15-2004, 11:38 AM
How about the manufacturer?

Kevin Watson
01-15-2004, 11:40 AM
Do we know the P/N for the IR emitters? I imagine just about any infrared LED operating at a peak wavelength of 940nm will work. The variables that immediatly come to mind are output power and radiating pattern. A data sheet for the part used to develop the IR beacon can be found here (http://www.lumex.com/gallery/images/cad_files/Oed-el-1L2.pdf). They're available from Digi-Key.

-Kevin

bfvaneyck
01-15-2004, 12:13 PM
Thanks Kevin,
I was looking for the specs so that I could find an emitter in a T1-3/4 package. We host competitions at our school and I need to make some decent beacons for the field.

Kevin Watson
01-15-2004, 12:34 PM
Thanks Kevin,
I was looking for the specs so that I could find an emitter in a T1-3/4 package. We host competitions at our school and I need to make some decent beacons for the field. Here is some stuff to consider for those building their own fields: The Lumex devices are what FIRST will be using on their official playing fields. Each official beacon will use seven LEDs. One important note: If you're building an official field, with two beacons running at the same time, drive the beacons with one EDU-RC because you don't want the IR sensors "seeing" multiple pulses arriving at the same time. Oh, another thing to look out for is beacon reflections.

-Kevin

Dave Flowerday
01-15-2004, 05:41 PM
One important note: If you're building an official field, with two beacons running at the same time, drive the beacons with one EDU-RC because you don't want the IR sensors "seeing" multiple pulses arriving at the same time.
That brings up a question I've been wondering about. What about regionals with multiple fields (or Atlanta, for that matter)? We've only gotten to play with the emitters/detectors a little bit so far but one single IR LED has no problem filling our entire practice room (which is a good deal larger than the field) with IR...

ChrisA
01-15-2004, 08:49 PM
Would there be a way to determine which of the two identical beacons from two separate fields arrived first, or is that out of the question?

I'm not very edumacated on IR. I'm pretty sure that everything would be fine if FIRST installed some lead walls between the fields (though I can't see that happening), but other than that I'm out of the loop.

deltacoder1020
01-15-2004, 09:29 PM
heh, or just get a wall of spectators :)

bfvaneyck
02-11-2004, 05:05 PM
Do we know the positions for the beacons, i.e. if you're standing on the blue alliance side of the field, is beacon #0 on the left or the right?