Re: [CAD_CAM_EDM_DRO] stepper driver

armadhas wrote:

> hi i am trying to find out if emc can drive a stepper driver
> that has cw and ccw inputs not step and direction

There are some very simple circuits that can convert step/dir
to CW and CCW pulses. Basically, the circuit looks like this,
assuming positive step pulses :

step -----
| ------
--------| \
| | O----- CW\
dir ---------------| /
| | -------
| |
| __|__
| \ /
| \ /
| O
| |
| | ------
| ----| \
| | O------ CCW\
--------| /
------

Note : horrible blobs above are 7400 NAND gates.
Inverter can be made from one NAND gate with both
inputs tied to input signal. So, it only takes one
chip per axis to do the conversion. (If you're
real cheap, you can actually do 4 axes with 3 chips,
as there are 4 gates per package.)

Jon