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lew247

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Joined: 23/12/2015
Location: United Kingdom
Posts: 1676

Posted: 07:53am 22 Apr 2016

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I know the Micromite has distance measuring capability using ultrasonic transducers.

Does anyone know of a way to measure distances up to say 50 Meters without using lasers?

Or does anyone know of a cheap laser module that could be used?
I know I could hack one of the laser tape measures sold online but it's extremely messy and not really what I'd like.

I thought about using IR led's but I think the distance would be less than using ultrasonics

Any ideas?

Edit: The reason I don't want to consider laser sensors is the cost of the units, I need this to be pretty cheap Edited by lew247 2016-04-23

redrok

Senior Member

Joined: 15/09/2014
Location: United States
Posts: 209

Posted: 11:49am 08 May 2016

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Hi Lew;

lew247 said I know the Micromite has distance measuring capability using ultrasonic transducers.

Does anyone know of a way to measure distances up to say 50 Meters without using lasers?

Or does anyone know of a cheap laser module that could be used?
I know I could hack one of the laser tape measures sold online but it's extremely messy and not really what I'd like.

I thought about using IR led's but I think the distance would be less than using ultrasonics

Any ideas?

Edit: The reason I don't want to consider laser sensors is the cost of the units, I need this to be pretty cheap

I think 50m is particularly hard to do both "Cheaply and Easily".

1. LEDs, with their wide divergence angle, just don't deliver enough power to the reflecting target to be useful, compounded by the return path losses. Plus the timing is done at the "Speed of Light".

2. Sound, as in ultrasonic, have similar problems, althou timing is easier as the timing uses the "Speed of Sound".

3. It could be done with a radio "Transponder" combined with ultrasonics. Use the sending unit to send out the ultrasonic pulse. The ultrasonic receiver hears the pulse directly and transmits the pulse back with a radio link. The advantage of this is the sensor hears the pulse coming in directly.

4. here is a link from Hackaday that is using a laser tape measure. I suppose this would not work well as it has to be accurately aimed.

I would think #3 would be the best choice. Radio links are easy to do. I suggest stuff from "LINX Technology". I have used the simple FM radio link to 1500m. OK I was sending digital data but it was very reliable.

You could have more than one widely spaced ultrasonic transmitter so you could get 2D triangulation. Or 3 to get 3D.

redrok

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