This sounds like a reflectometer of sorts. Or an acoustic wave detector.
The times that you are suggesting make a software solution difficult. It
looks like you need to be taking an excursion into the world of _very_
_fast_ DSP engines.
I would first explore the possibility of using a hardware solution along the
lines of a period counter and two fast comparators.
At time zero, reset a fast, high resolution, period counter and enable
comparator 1. Edge detection by comparator 1 should start the counter,
disable itself, and enable comparator 2. Edge detection by comparator 2
then stops the counter and notifies somebody to come collect the current
sample.
The comparators should have adjustable thresholds to that each can be
taylored to its respective peak's amplitude.
Good luck, Bob Smith
--- Avoid computer viruses, Practice safe hex ---
-- Specializing in small, cost effective
embedded control systems --
http://www.smithmachineworks.com/embedprod.html
Robert L. (Bob) Smith
Smith Machine Works, Inc.
9900 Lumlay Road
Richmond, VA 23236 804/745-1065
[EMAIL PROTECTED]
----- Original Message -----
To: "Multiple recipients of list CHIPDIR-L" <[EMAIL PROTECTED]>
Sent: Wednesday, February 18, 2004 9:24 AM
> > The minimum time between 0, peak1 and peak2 is the vital
> information you
> > didn't give us. Gathering that it will all happen in 50uSec, peak
> > detection would be difficult. Certainly timing form 0 to peak would be
> > difficult.
> Something in the range of 1usec to maybe even 1 millisec.
> There is a relatively large gap between 0 and peak 1.
>
> I could detect the voltage level of the first peak. But I do
> not know the level of the second peak, I do know that it is
> lower, but it varies. That is why software is interesting.
>
> > Can you use the voltage value for peak 1? If there is a constant filter,
> > that might work. Another lazy approach if the pulses are symmetrical
> > would be to feed them into a digital 'delay line', and pick out the
> > midpoint. Here's what I mean
> > > | /\
> > > | / \
> > > | / \ /\
> > > |____/ \___/ \__ becomes the following pulse train
> > 000000000111110000011000
> The pulses are not neat, they have some ringing.
>
> > You'd probably sample a bit faster than that, but you get the idea.
> > Either way, your software wouldn't have to break out a sweat.
> > Declan Moriarty.
> > Author: Declan Moriarty INET: [EMAIL PROTECTED]
>
> Regards,
> Pieter Hoeben
> ______________________________________________
>
> Hoeben Electronics Phone: +31 6 51590081
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> ______________________________________________
>
> --
> Author: Pieter Hoeben
> INET: [EMAIL PROTECTED]
>
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