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measure distance between two adrinos (Xbee?)
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measure distance between two adrinos (Xbee?)

by bwells on Wed Mar 11, 2009 7:38 am

Can someone suggest how I could measure the distance one Arduino/XBee is from another Arduion/XBee?

How far away can an an XBee be from another Xbee and still give me an accurate distance measure (if its even possible)?

If not XBee, is there another device that would help? Perhaps use the XBee to send the data to a base station, but use some other device to help measure distance.

Thanks
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Re: measure distance between two adrinos (Xbee?)

by adafruit on Wed Mar 11, 2009 6:22 pm

xbees dont do any sort of distance measurement

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Re: measure distance between two adrinos (Xbee?)

by Ran Talbott on Wed Mar 11, 2009 11:28 pm

If you have a clear line of sight, you could use something like an ultrasonic rangefinder to measure distance. If they're a significant distance apart, you could use GPS to measure position (as long as the GPS error is acceptable) and calculate distance.

Ran
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Re: measure distance between two adrinos (Xbee?)

by bwells on Thu Mar 12, 2009 7:52 am

Line of slight is reasonable. Can you say anything more about the ultra sonic range finder and how that would go with an arduino? Is there a shield for one of these or do you have any ideas for how that would be accomplished?
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Re: measure distance between two adrinos (Xbee?)

by franklin97355 on Thu Mar 12, 2009 6:55 pm

What kind of distance are you talking about? Ultrasonics have a limited range, probably less than 10ft. Also except for the LV-MaxSonar-WR1 most do not do well in the elements.

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Re: measure distance between two adrinos (Xbee?)

by bwells on Thu Mar 12, 2009 7:39 pm

I am thinking of a few hundred feet. But it would be flat and clear of obstructions. But it would be outside. I can build enclosures.

It seems like such a basic idea. I know for example that they have used some kind of device to track large numbers of tuna in large net-enclosed breeding sites. So they have some way to do that.

Imagine having a big fenced in field with a "sensor" at each corner. Then in the field, you could have motorized toy cars for example that drive around and I want to get a view on my computer of where they all are relative to each other. If I can find out how far each car is from each of the 3 or 4 corners of the fence, I can do all I need and then send the values via XBee to a base station.

Given all the cool stuff that Arduino does and all the shields; I was dreaming (really dreaming) that maybe the technology would exist to do what I am talking about.
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Re: measure distance between two adrinos (Xbee?)

by eil on Thu Mar 12, 2009 9:06 pm

What you speak of sounds suspiciously like triangulation or direction finding which is a decidedly non-trivial application. (For me, at least. Maybe a ham could help?) I certainly don't know of any arduino project that would work on the scale of a few hundred feet.

Putting a Arduino with XBee + GPS receiver on each thing to be monitored seems like the easiest way to go, if you don't mind the accuracy being only 6-10 feet.
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