I'm building a CNC mill based on Patrick Hood-Daniel's machines
I'm also playing with Arduinos, and I'm beginning to wonder if I have this right:
I have 5v 1A steppers.
I'll be using EMC2 (Linux-based CNC) to run the whole thing and I had intended to feed the output from the Ubuntu box that's running EMC2 into an Arduino that then splits the data and sends it to three stepper drivers, probably built with sn754410ne h-bridges.
I had thought of possibly building the controllers with an ATtiny2313 per motor.
Is this overkill? Is the Arduino even required or can I feed the h-bridges directly from the EMC2 output?
My main worries are that the Arduino won't be able to control three motors concurrently, although there is a new library available: http://www.open.com.au/mikem/arduino/AccelStepper/ that purports to achieve this, and also that I won't be able to get half-stepping (or finer) with this setup.
Best Answer
I would choose the more modular support, with that ATtinys running the motors, with the ATtiny you could add extra features like position, or encoder data, emegency start/stop and other features. As for the main control unit, the arduino may be under powered for fast work but it is possible.
you may want to also look at the Reprap project for more idea for hardware. another resource that may help is the emc2 supported hardware.
you would not be able to hook up emc2 right to the steppers with out have some sort control module.