20m Ultrasonic Rangefinder

[lanternfish]

Hi everyone.

Does anyone know of an Ultrasonic Rangefinder module that can measure to 20m? Have searched forum and some very good info on range finding, just need a module if one is available.

Cheers

 

[Dippy]

Sorry, I don't know of a module (I'll leave the Googling to the experts), but I have come across a DIY solution (almost).
http://uk.farnell.com/prowave/pw0268/smd-sonar-ranging-smd-ssop20-20/dp/1007371

Data Sheet suggests 18m possible (page 6). But there are probably numerous ways to make something beefier if you want to go the DIY route. I'm sure there were some tranducers made by Polaroid that were meant to be good. Can't remember, sorry.

Nothing on Ebay/Alibaba ?

 

[BeanieBots]

Sorry, I don't know either.
I've done quite extensive testing (and modifiying) of the readily available modules by the likes of Devantec but have never been able to get beyond around 12m even with modified gain sections and ideal conditions.

The next step of these 'hobby' range finders seems to be a step leap to the km range and those cost $$$$.

You may well have found a gap in the market for mid-range units.
As suggested by Dippy, polaroid (used to?) produce a transducer which can be driven harder than the 'standard' units. Combining those with extra drive and extra sensitive gain modules MIGHT produce something useable. Though even the smallest breeze at those ranges could have significant consequences.

 

[gbrusseau]

I have always thought this mechanical range finder device could be modified with say a laser to get long range, but have not devoted any time on it. Maybe someone can provide a proof of concept idea.

http://www.bizarrelabs.com/rngfndr.htm

 

[BeanieBots]

Interesting concept.
I guess it could be done with lasers or even a simple IR LED.
You would need to modulate the transmitted light so that your detector (in place of eye/mirror) could determine it was the sent signal being recieved.

 

[slimplynth]

A friend sent me the link below, as a warning, after saying I'd bought the IR thermometer from Maplins.

http://www.dailymail.co.uk/news/article-1164447/Anglers-arrested-DNA-tested-anti-terror-police-using-laser-pens-scare-ducks.html

 

[papaof2]

Does anyone know of an Ultrasonic Rangefinder module that can measure to 20m? Have searched forum and some very good info on range finding, just need a module if one is available.

I haven't seen anything in the "hardware store" units that is rated to measure that far. Simple unltrasonic transducers produce a fairly wide beam, so the space to be measured must be clear of potential false targets: a 10m wall with a large picture hanging on the wall 5m away from you will likely measure 5m. The laser rangefinders are much more accurate (and similarly more expensive).

John

 

[lanternfish]

Thanks for all the replies.

Google didn't turn up anything of hobbyist grade. There are some modules that allow you to adjust the 'beam' angle. Max range was 11m.

Oh well, back to the drawing board.