Re: Was Chopper circuit - Now ver 3.2, G298

At 23:14 09/04/2002 +0000, you wrote:

>Just thinking; I recall someone on the list that has already replaced
>the 'L297 with a PIC. And the PIC could be the heart of a single axis
>"jogger", for a 4th axis rotary table, for example. Kinda like
>Sherline's controller? (Bill's ears perk up). I don't know if it's any
>cheaper, but some things like limit and E-stop switches could be built
>in. Same for PAL (or eqv).

Done that...I have an initial production run of single-axis
PIC/L297/L298-based rotary table controllers in progress right now...am
working on the documentation as we speak. Headline specs:

-Will handle any drive ratio between 1:1 and 99:1 - software settable
-Software settable motor current up to 2A/phase
-Idle current can be set as up to 50% of the motor current
-Supply voltage up to 40V
-Jogs in increments of +- 1/100th, 1/10th, 1 or 10 degrees
-Division mode handles all divisions from 1 to 999
-Degrees mode handles any angular move in range 0.001 to 360.000 degrees
-All moves calculated to the nearest 1/2 step - errors are evenly
distributed to avoid cumulative errors creating the "thick or thin tooth"
problem. Display shows desired position and actual angular position
-Can be driven via external step-and-direction signals to use as a "true"
4th axis
-Can be used to drive an external power stage via step-and-direction
signals to allow higher power motors to be used
-Controlled/configured via a 16-key keyboard & a 2-line by 16-char LCD display.

Pics & fuller specs to follow...

Regards,
Tony