Re: Optical encoder parallel port hookup?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Abby Katt
<cncgroupnospam2@...> wrote:

>
> Hi Folks,
>
> Really simple question - I can't seem to find the answer on google or
> searching my old CNC/MACH2 messages tho.
> I have an optical encoder I want to hook to my parallel port (to use as
> a handwheel in Mach).
>
> It runs on 5V, and has two outputs - A&B. The 5V+- is already solved,
> but I was wondering about the two phase wires, so I just connect them
> straight to input pins on the parallel port?
> Or do I need some arrangement of resistors, etc?
>
> Thanks!
> -Abby

The encoder most likely has pullups on the outputs or they are totem
pole outputs that don't need pullups. You should be able to connect
them directly to your parallel port pins and map those as encoder
inputs. If you have a BOB with input isolation then the encoder +5
needs to be referenced to the outside ("dirty") ground used for homes
and limits.

>
> (http://www.silverkatt.co.uk)
>