Lpc2000

They're measuring distances of kms, to an acuracy of 6m (still in 
the 20ns range in terms of time, though).

As I said, a tough enough job using a standard micro. I think if 
you're going to use this technique, you'd need some piece of 
hardware on the front-end with a fast clock driving it to get the 
kind of acuracy to make it useful. In which case, the speed of the 
micro isn't too relevant.

There are other better approaches, I'm sure.

Brendan

--- In lpc2000@yahoogroups.com, "Leon Heller" <leon.heller@...> 
wrote:
>
> ----- Original Message ----- 
> From: "Onestone" <onestone@...>
> To: <lpc2000@yahoogroups.com>
> Sent: Tuesday, May 16, 2006 3:15 PM
> Subject: Re: [lpc2000] Re: Hello all....
> 
> 
> >I thought the commercial systems used phase shift to determine 
distance?
> > 
> 
> Some measure the time for the pulse to return:
> 
> http://www.acuityresearch.com/products/ar4000/index.shtml
> 
> http://near.jhuapl.edu/fact_sheets/NLR.pdf
> 
> Leon
> ---
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