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Author Topic: Sharp IR interference  (Read 2552 times)

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Offline StephanieTopic starter

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Sharp IR interference
« on: July 30, 2009, 10:21:19 PM »
Hello guys!

I was looking at SoR member tutorials and saw this:



I plan to make an identical setup (side-by-side, tilted horizontally), but I don't know if they'll interfere with each other (I've never used Sharp IR).

Has anyone here ever tried to put IR Rangefinders that way? I don't have the sensors here to test...
« Last Edit: July 31, 2009, 12:18:13 AM by Stephanie »
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Offline StephanieTopic starter

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Re: Sharp IR interference
« Reply #1 on: July 30, 2009, 10:24:41 PM »
Double post, sorry
« Last Edit: July 30, 2009, 10:28:07 PM by Stephanie »
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Offline SmAsH

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Re: Sharp IR interference
« Reply #2 on: July 31, 2009, 01:44:55 AM »
well, as long as the beams don't interfere with one another there shouldn't be a problem...
one other thing you could do is have them going off one by one if interference is a problem.
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Offline wil.hamilton

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Re: Sharp IR interference
« Reply #3 on: July 31, 2009, 06:03:20 AM »
unless the beams were completely out of phase with one another (in which case they would disappear) there should be no problem.  The way the sharp ir works is by reflected IR light, so, more ir light to reflect you'd think would be better (although, i could be wrong here...., this is just my intuition talking here)
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Offline Soeren

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Re: Sharp IR interference
« Reply #4 on: July 31, 2009, 06:48:33 AM »
Hi,

Quote from: SmAsH on July 31, 2009, 01:44:55 AM
well, as long as the beams don't interfere with one another [...]
Hey, this isn't The Ghostbusters ;D

If one unit can "see" the other units beam, the range _will_ be upset in some degree.
If that's the case, break them apart and synchronize them.

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Søren

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Offline emoseman

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Re: Sharp IR interference
« Reply #5 on: August 04, 2009, 10:44:38 AM »
Out of curiosity why would the the IR sensors be placed so close together?  Wouldn't one suffice?  Or are you trying to get a wider range of depth detection with an IR sensor?

Would a single IR sensor mounted on a servo that swings the sensor back and forth work to the same effect?

Just thoughts...

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Evan
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Offline wil.hamilton

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Re: Sharp IR interference
« Reply #6 on: August 04, 2009, 10:52:18 AM »
@ evan:

they could have different ranges
one could be for farther away (30cm to 1m)
the other could be for up close (4cm to 30cm)
that way you have a better fidelity reading of your environment
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Offline emoseman

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Re: Sharp IR interference
« Reply #7 on: August 04, 2009, 10:54:44 AM »
Ah that makes sense, I hadn't thought of that...

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Evan
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Offline StephanieTopic starter

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Re: Sharp IR interference
« Reply #8 on: August 04, 2009, 06:19:01 PM »
Actually, the reason is this: in the competition I'm participating, there is a limitation in the number of motors. A servo is, in theory, a DC motor. And, since I need to follow my opponent (it's sumo), I need at least two to decide where to turn (if the opponent escapes from one of the sensors). The max number of sensors I can use is high, so I'm using two there.
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Offline emoseman

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Re: Sharp IR interference
« Reply #9 on: August 05, 2009, 01:36:26 PM »
Ah gotcha, that makes sense too. :)

Good luck in the competition!

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Evan
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