Quote Originally Posted by bobc View Post
It is entirely possible, it is what all the Reprap printer controllers do, they take GCode sent from a PC over RS232, plan the motion and control the steppers, and on the 8 bit Arduino platform. There is also software for CNC, have a look for GRBL.

It is the sort of project you can do from scratch, you may not achieve reliable motion control on the first go, but steppers are quite easy to work with. If you have got a Pi, you may as well use it. The nice thing about the Pi is you can use a nice sized display with it.

My Pi should arrive any day now!
I'll have a look...

The nice thing about the Pi is the fact that, while you could plug a display in, if you were to use Linux you could equally remotely view/control it with VNC. I want to add this to a new PCB mill I am planning that can sit inside a sound-proof box on the next bench but I can watch it on the main PC... without tying up the main PC and without taking up the space of another PC...

For what I have in mind, I think it could be done without a real-time kernel with a 'device driver' hooked into a higher priority interrupt and a shared memory queue of simple motion commands. Sort of like a smoothstepper in software... I did something like this more than a few years back in Windows 95 for a real-time data transponder so I know the concept works, but I need to learn more about the Linux low level stuff.... and thats proving hard to find an easy way in...