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[DPRG]Wall-E -> 1GHZ computers laser rangefinding

Subject: [DPRG]Wall-E -> 1GHZ computers laser rangefinding
From: ray xu rayxu at tx.rr.com
Date: Sat Jul 5 11:44:30 CDT 2008

Well if you search "counters" on onsemi, there are results of some counters
that have an fmax of over 1 gHz.  The only problem with that is that I don't
know how to solder SMD parts, they are rare to find, and also I remember
saying that working with frequencies above 20mHz on bread board is ugly.

______________
Ray Xu
rayxu at tx.rr.com

-----Original Message-----
From: dprglist-bounces at dprg.org [mailto:dprglist-bounces at dprg.org] On Behalf
Of Dean Hall
Sent: Saturday, July 05, 2008 11:14 AM
To: dprglist at dprg.org
Subject: Re: [DPRG]Wall-E -> 1GHZ computers laser rangefinding

I'm not aware of any commercially available counters that operate at  
that speed.  Are you?  The fastest logic families I've seen top out  
around 2-4 ns switching which is 3 orders of magnitude too slow.

!!Dean


On Jul 5, 2008, at 10:50 , Rud Merriam wrote:

> Hi,
>
> The CPU does not need to run at 1 GHz for this situation. Only the  
> counter needs to run at high speed and accept interrupts that start  
> and stop the counter. A separate counter chip is my suggestion.
>
> 1. Start the counter and the light pulse.
> 2. When the light pulse returns turn off the counter.
> 3. Read the counter when convenient.
>
> Rud Merriam K5RUD
> ARES AEC Montgomery County, TX
> http://TheHamNetwork.net
>
> -----Original Message-----
> From: ray xu [mailto:rayxu at tx.rr.com]
> Sent: Friday, July 04, 2008 7:08 PM
> To: dprglist at dprg.org
> Subject: RE: [DPRG]Wall-E -> 1GHZ computers laser rangefinding
>
> Dean: I see why the breadboard is a bad idea.  All I need from the  
> controller is because I need to interface 1gHz counters to it.
>
> Ron: I am already done with my sonar project.  All I need to do now  
> is to put it on a board and in a project box.  Also, I did some  
> searching, and the closest thing (http://www.repairfaq.org/sam/lr/)  
> I came to says that it uses a computer controller.
>
>
> Heres my theory of operation:
>
> The controller will be instructed to trigger a laser pulse (650 nm  
> laser diode), start a timer/counter, wait for the beam to come back  
> (receiver: OPT101 with concave   lens on top of photo-sensitive  
> area), disable the counter/timer, do some calculations, display  
> results, and loop.
>
>
> ___________________
> Ray Xu
> rayxu at tx.rr.com
> DPRG member
> OOPic group member
> Seattle Robotics group member
> My Blog
> Custom HTML generated signature upon sending
>
> -----Original Message-----
> From: dprglist-bounces at dprg.org [mailto:dprglist-bounces at dprg.org]  
> On Behalf Of DeltaGraph at aol.com
> Sent: Friday, July 04, 2008 2:59 PM
> To: dwhall256 at gmail.com; dprglist at dprg.org
> Subject: Re: [DPRG]Wall-E -> 1GHZ computers laser rangefinding
>
>
> Dean / Ray
>
>
> Dean,Good point on Ray's project.
>
> I guess the question is to find out what you are trying to do, Ray.
>
>
> That is, if you are attempting to measure time of flight of light  
> you may be talking an advanced project where specialized hardware/  
> knowledge might be needed.
>
>
> Reference designs are a good place to start.
>
>
> Yeah, breadboarding   in this range would be out.
>
>
> Might suggest playing with sonar first. You will learn a good deal  
> and sound's propagation rate is 1 millionth the speed of light.  
> Master that first. Just Me Talking.
>
>
>
>
> Ron
>
>
>
>
> Gas prices getting you down? Search AOL Autos for fuel-efficient  
> used cars.
>
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> 7/3/2008 7:19 PM
>
>
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