Thanks to all who responded. As usual, the PICList is a wonderful source 
of information. Where else can you tap into a knowledge base of 2000+ 
engineers, technicians and scientists?

I think this is not an earthquake, but blasting of some kind nearby. So, 
I'm not sure that what I need is a seismometer, exactly. It shakes the 
house, so I thought to attach the device to the wall of my second story 
bedroom.
The three foot mechanical pendulum might work, but I need something that 
will log the disturbance. We won't be standing there when it occurs.

So I'm still thinking my best option is the accelerometers. I found some 
nice pcb assys' on Sparkfun electronics site:

http://www.sparkfun.com/commerce/categories.php?cPath=23_80

I'm on vacation next week, so it will be a while before I get to this.

Thanks again,
Mark


Jinx wrote:

>The September 05 issue of Silicon Chip has a Build Your
>Own Seismograph project
>
>Full article is not available on-line but I can supply details
>if you're interested
>
>http://www.siliconchip.com.au/cms/A_105119/article.html
>
>The detector is an opto-sensor on the end of a magnetically
>damped horizontal pendulaum
>
>A link in the article to the author
>
>http://science.uniserve.edu.au/school/Seismograph/
>
>
>
>  
>

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist