[clug] O/T Digital Position sensing

[Keith Goggin]

David Tulloh wrote:
> Ben Nizette wrote:
>> On Tue, 2009-11-03 at 11:11 +1100, Keith Goggin wrote:
>>  
>>> I need to know the position of a shaft ...
>> The /simplest/ thing for absolute position I can think of given the
>> limited range is a potentiometer and ADC.
> They come packaged together and are generally referred to as encoders.
> 
> Farnell sells them from $10,
> http://au.farnell.com/absolute
> 
> Incremental (relative) encoders are much cheaper and start from $1.50.
> http://au.farnell.com/incremental
> 
> I would recommend one of those over hacking up a mouse.  You get a 
> better end result with known specs for only a few bucks.

Ok Thanks all, I've got a bit of reading to go on with. I particularly
liked Andrew's "Good Use of Technology"

Responding to the various requests for more detail, my project is to
monitor a throttle shaft setting in an automotive environment. The arc
of rotation is about 90 Degrees. The accuracy required is about +/- 2
Degrees.

Initially I only need to identify two points in the range of throttle
settings but provision for more would be useful.

My initial attempt involved a cam/micro-switch setup but I found engine
vibration made this impractical.

I see Jaycar Electronics have Hall Effect Kits so next time I'm in
Fyshwick I'll have a look.

Thanks again