EasyDriver 4.2 and Stepper
I didn't get around to hacking the Arduino this weekend since I had to do a bit of work. (Besides I spent saturday reading up on, and experimenting with, Grails since that was a more "couch compatible" activity.)
While the goal is still to figure out if i can use the Arduino Mega to implement a gcode interface I suspect that once the CNC rig is built I might get a bit impatient and use one of the parallel port hacks to hook it up to a machine. I still know too little about the Enhanced Machine Controller (EMC) package so I should probably read up a bit on that and install it on a spare computer I have lying around.
I also need to understand the Atmel microcontroller a bit better. I have this vague idea of a scheduling-based platform for controlling the steppers, reading serial input and possibly controlling a small status display. To do that I probably need to experiment quite a bit with timing and see if it is practical to write interrupt handlers. I could really use some advice from more seasoned Atmel programmers, so if any if you find these things interesting, please do not hesitate to contact me.
There are a lot of people who want a "headless" setup for their CNC machines -- meaning they would like to dump gcode to an SD card and be able to run the gcode without having a computer hooked up. Possibly with a small filesystem browser on a 2-line LCD so you can select which gcode file to run. This is not a big priority for me right now, but a cool idea.