Or you could use a simple microphone with an analog comparator. Check around
in the web pages for analog synthesizers about using piezo speakers as
triggers. You also wouldn't have to debounce the input as you would with the
scheme shown below.

-----Original Message-----
From:   pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU] On
Behalf Of Timothy D. Gray
Sent:   Thursday, July 09, 1998 2:22 PM
To:     PICLIST@MITVMA.MIT.EDU
Subject:        Re: Bouncing Ball Detector

A simple robot impact sensor would do...
--------------+------- +vcc
*            *
--------------+------- TO PIC
Two pieces of metal with insulators at the end... one wire on each plate..
voila! vary the thickness and size of the plates to adjust sensitivity.

On Thu, 9 Jul 1998, Rock Thompson wrote:

> In an effort to further the athleticism of my children, so they can
> someday be filthy rich and support their kindly old father, I am
> building a wooden target for them to throw a ball at.
>
> I want to count the number of times the ball hits the target.  A PIC
> will count the number of hits and handle an LED display.  But I'm
> hoping for suggestions on how to detect the hits.  Two things come to
> mind: An accelerometer responding to the vibration of a hit, or a
> microphone that picks up the sound of a hit.
>
> Any further ideas or comments?
>
> Thanks, Rock
>
>
>
>
> _________________________________________________________
> DO YOU YAHOO!?
> Get your free @yahoo.com address at http://mail.yahoo.com
>