Quoting ivp <joecolquitt@clear.net.nz>:

>> If using a slide pot, you can change it's range mechanically ... think
>> gear-shift in a car.
>
> The client is thinking 9mm or 10mm distance between track names in
> the playlist (= 171mm or 190mm travel overall by the pointer) and a
> pot is around 60mm so a 3:1 reduction gear would do the conversion.
> He had a printout the other day on an A4 but I don't have a copy so
> can't confirm the distance he picked
>
> A good little thought exercise
>
> wbr

Actually, if using a mechanical reduction, you might as well use a  
rotary pot for this.  Or wouldn't a rotary pot + encoder be better  
(the encoder will add accuracy to the rotary pot's info)?

That now makes me think of using a series of IR LED's in a line with  
one IR sensor under the "switch".  The IR LEDs would come on one at a  
time (cycling very rapidly) while checking the IR sensor to see which  
LED it is receiving the highest signal from it.  Ahhhh... memories of  
trying to implement a touch screen on a TRS-80 a few decades ago.

Cheers,
-Neil.



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