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Unread 05-03-2004, 18:58
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Norm Hurst
AKA: gnorm
#0381 (The Tornadoes)
Team Role: Programmer
 
Join Date: Jan 2004
Location: Trenton, NJ
Posts: 138
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Re: Why not analog sensors??

Quote:
Originally Posted by Kevin Watson

Quote:
Originally Posted by gnormhurst
Some may think that "1" or "0" is a much cleaner, noise-free signal than an analog signal, but it is nearly information-free as well!

You're kidding, right?

Not at all, I was thinking "information theoretically". One bit is the smallest amount of information. 10 bits is a lot more. Now, it also depends on bandwidth and noise, and if the one-bit case is fast enough, you can get a lot of information.


Quote:
How would you discriminate against all of the other sources of 940nm infrared? Would you use a different wavelength for the other beacon?
I was thinking of using, say, a 40 kHz beacon (CW, not pulsed) and have another frequency for the other beacon, say, 33 kHz. The rub is that to implement the dual-tracker system I think you would need eight sensors instead of four (four for each beacon frequency). $$$


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There's nothing preventing you from doing this. Radio Shack carries infrared phototransistors.
Lack of time prevents me, at least in a 6-week build cycle. Maybe I can play with this in the off season. sigh....



BTW, I'm here at the regional in Trenton, NJ, and when I asked which beacon was "1" and which beacon was "0", I got some pretty blank looks. I said, "You know, the IR beacons for IR tracking?" More blank looks. They found someone from IFI who made a few calls and learned that "this" beacon is connected to pwm01 and "that" one is on pwm02.

But I still can't get it to work. Tomorrow we will have our test beacons, so maybe we can get some answers. It's pretty hard to debug with only one run every 90 minutes, with no telemetry, just observing the robot from the stands about 200 feet away!


Quote:
*sigh*
Exactly.


-Norm

Last edited by gnormhurst : 05-03-2004 at 19:11.