AVR-Chat

On Jan 15, 2009, at 10:47 AM, David VanHorn wrote:

>> It thought it sounded like a homework assignment. Therefore one is  
>> free
>> to stipulate conditions that are not specified.
>
> Yeah, it kinda does sound like homework..
>
> Asking for ideas is cool IMHO, he's not asking for us to SOLVE it for
> him, provide tested code, and assembled PCBs with complete BOM and
> programmed micros... :)

Ditto. Big difference in asking for ideas. Much the same as a group  
discussion about a book from assigned reading vs. asking for a pre- 
written book report.

I have spent some time considering ultrasonic range finding as a means  
of measuring wheel travel on a dirtbike. Optical encoders are a  
possibility but we're talking about measurements under very nasty  
conditions. Measure the travel of *this* wheel: http://home.hiwaay.net/~dkelly/Husaberg/Pages/4.html

String and pulleys would be fairly complicated but easy to understand.  
Complex to install, especially when its not intended to be a permanent  
installation.

What I'm thinking would work best would be a pair of telescoping tubes  
with piezo exciter and microphone. Then either time how long the  
wavefront takes to echo off the end or excite with white noise and  
measure the frequency.

The same telescoping tubes should work just as well for the front forks.

Think an accelerometer on the wheel and on the fender would also be  
good to have. Not sure that the job could be done with only an  
accelerometer but having both acceleration data and absolute position  
data one could validate each with the other. Then learn how to live  
with only one or the other for future use.

--
David Kelly N4HHE, dkelly@HiWAAY.net
========================================================================
Whom computers would destroy, they must first drive mad.