[ I'm using the PIC tag for this for now, as there is some PIC  
content, and we really need to see more of the PIC tag on this forum  
lately. ]

I'm searching for a multi-axis stepper-motor motion controller, but  
the options I've found so far are pricey, so that leads to the thought  
of rolling my own.  Don't really need another project right now, but  
I'll make the time for it if it saves me a few hundred $$$.

My requirements are relatively simple... Interface to a PC (parallel,  
RS-232, USB, or I2C) to accept commands to move to a 3-dimensional  
vector position (X,Y,Z) with a certain acceleration and max speed  
value.  The controller will move to that position (coordinated),  
accelerating and decelerating accordingly, and sending back some  
signal to indicate that it's completed that operation.  Future  
embellishments may include reading quadrature encoders to verify that  
moves are successful. The controller will need to output only step/dir  
signals for each axis, which will go to individual drivers.

So my questions...
(1) Know of any simple 3-axis controllers that will do this at a  
relatively decent cost?  I'd need it to provide the interface protocol  
spec, or a Linux library/API.

(2) Know of any projects/circuits on the net that does this?

(3) Know of any controller chips that will make this easy?  I found a  
similar-ish controller by National semi (LM629), but it was for DC  
servo motors.  Would be great to find a similar stepper chip.

(4) As I also consider the home-brew PIC option, I'm wondering which  
PIC would be suitable.  There would be a good bit of math, and rigid  
timing.  I've only used PIC 16F's and 18F's to date, but I expect on  
of the dsPIC's or 32-bit options would be ideal.

Cheers,
-Neil.




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