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Topic: distance sensor (Read 87 times) previous topic - next topic

kdarius

Hello,

I was asked an interesting question and was wondering if anyone had any thoughts.  We were taking about having a light in the middle of a field and the closer you got to the light the brighter it would get.  we are only talking about 5 feet.  Anything farther then 5 feet would be off and anything closer then 5 feet the light would get brighter until you are almost touching it.  I thought about a kinect but the issue is its in daylight so kinect does not work.  Anyone have any thoughts?

johnwasser

Enough ultrasonic distance sensors to cover all directions.  The HC-SR05 can be had for under $2 each: http://www.fasttech.com/product/1012007

They are supposed to cover 4.5 meters (over 14 feet) so it should work fairly well at five feet and closer.

The sensor angle is shown as "Not more than 15 degrees" so you will need at least 24 of them for 360-degree coverage. Alternatively you could mount fewer sensors on a ring that allows then to be swept with a servo.  You can take readings every 5 or 10 degrees and use just 6 or 8 sensors to cover a much wider angle.

Another possibility is a bunch of bright IR LEDs and a few IR sensors.  You can measure the difference between LEDs On and LEDs Off to get some information about the proximity of an IR-reflective object.
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kdarius

John thank you for your reply,
So the HC-SRO5 creates ultrasonic sound that would bounce of someone walking by and get picked back buy by the sensor?

the problem with the IR leds is im not sure how that will work in sunlight.  There might be to much IR noise. 

weedpharma

IR distance sensors use a modulated send signal so that it can detect its own signals.

Weedpharma

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