CNC machine

Hi all,

i was wondering how you control a stepper motor...

in that way that you can control is speed...

i was thinking of a variable resistor...

conected to a PIC...

who measures the voltage etc...

but i don't know yet how to control the rpm of a stepper motor..

i also was searching for L297 examples

and should a pic 20Mhx (16F877a) be enough or should i go for a 18FXXX

then my last question...

is it easy for the pic.. to manage a serial eprom to be able to buffer data..
because large cnc progs maybe don't fit in the pic..

or should i give the pic his data realtime..????


TKS

TKS said:

Hi all,

i was wondering how you control a stepper motor...

in that way that you can control is speed...

i was thinking of a variable resistor...

conected to a PIC...

who measures the voltage etc...

but i don't know yet how to control the rpm of a stepper motor..

Click to expand...

All you do is control the frequency of the steps, there's a certain speed above which they won't move, anything below that is fine - a step a second, a step a minute - anything you like. Maximum speed is usually only about one revolution per second or so.

i also was searching for L297 examples

and should a pic 20Mhx (16F877a) be enough or should i go for a 18FXXX

Click to expand...

A 4MHz 16F877 would be plenty, or a 16F628 - there's nothing hard about driving a stepper motor.

then my last question...

is it easy for the pic.. to manage a serial eprom to be able to buffer data..
because large cnc progs maybe don't fit in the pic..

or should i give the pic his data realtime..????

Click to expand...

Probably as well to send the data from the PC as needed, let the PIC handle what it's got then ask for more.