[sdiy] Rotary encoder

[Tom Wiltshire]

On 11 Jan 2009, at 16:03, Simon Brouwer wrote:

> Ingo Debus schreef:
>> If you want to interface a standard 1 * 12
>> rotary switch to a microcontroller without additional circuitry you
>> need 12 inputs.
>
> Or 11 resistors and one A/D input.
> Nowadays even very cheap microcontrollers have A/D.

PIC 12F675 would do it. 6 i/o pins, so you use one as an A/D input,  
and four as your outputs. The chip costs less than a £1, and the  
associated code would take ten minutes.

Still, I don't really see why you can't just use a 16-position hex- 
coded rotary switch with an end-stop at 12 positions. After all, this  
thing that we're spending time trying to invent does actually already  
exist!

T.