Isaac how does that work? Would the uC switch between each extended pin
many times per second?
On Sep 13, 2015 8:24 PM, "Isaac Marino Bavaresco" <
isaacbavaresco@yahoo.com.br> wrote:

> The OP could use the 74HC597 to serially expand the number of inputs.
> Usually it would need three I/O pins, but with a clever trick it is
> possible to use just two.
> It is possible to expand the input pins to virtually any number, in
> multiples of eight.
>
> Isaac
>
>
> Em 13/09/2015 20:13, IVP escreveu:
> >>> Thanks.   I am only looking for 5 bit accuracy.
> >>>
> >> That might be asking a bit much - not from the PIC, that's easy
> >> enough - from the person.
> >> 5 bits =3D 32 position values. Typical pot has about 270 degrees
> >> of travel. 270 / 32 =3D ~8.4 degrees.
> > My nephew has a guitar effects box, and one of the selectors
> > looks rather like that on a DMM, but is actually a pot with 10
> > detent positions between fully CCW and fully CW, giving 12
> > distinct settings altogether. The knob is spring-loaded against
> > a ring of bumps in the case plastic
> >
> > Maybe you can make something with a slotted disc and a ball
> > bearing and a spring or other bits and pieces. 32 values is going
> > to be tricky though.
> >
> > 10-turn pot ? With vernier ?
> >
> > Analogue TVs had slide pots with a screw thread for tuning
> >
> > Two thumbwheel or BCD switches, 10s and 1s ?
> >
> > How about an optical encoder, bought or made. You could
> > print a scale on a transparency. Perhaps 5 rings to represent
> > 5 bits in a simple binary code, or 1 ring of stripes to generate
> > pulses to count
> >
> > There are many variations of digital calipers, protractors and
> > rulers you could take apart for a very fine position sensor
> >
> > Pehaps hack an optical mouse. Draw a circle on the screen
> > now with it. Can you potentiometerise that ?
> >
> > All options have drawbacks - accuracy, precision, consumption,
> > reset on power-down, cost, fiddliness etc
> >
> > Joe
> >
> >
> > -----
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> 09/13/15
> >
>
>
>
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