For anyone looking for a DIY way to make a CNC 3D printer, router, plasma cutter, and/or milling machine and want some serious CNC host software (like LinuxCNC) to control it, We've got you covered.

You can use HAL2Arduino to give your Arduino based creations an uplink to LinuxCNC. You can even control multiple Arduinos simultaneously!

HAL2Arduino is a communications layer (or framework) that exposes LinuxCNC variables and hooks for you to play with from the comfort of the Arduino platform.

If your interested, you can read about it on our blog at http://emc2arduino.wordpress.com/ or download a copy yourself from https://github.com/dewy721/EMC-2-Arduino/tree/master/Downloads/HAL2Arduino.

If you have questions, just ask.

From the Author of Emc2Arduino:
I've seen a lot of posts on people interested in making a DIY CNC machine, then struggling to make a decent gcode interpreter sketch for it.

If that sounds like you, I've already got you covered. The newly released HAL2Arduinobrings OpenGL accelerated CNC control software to your very own Arduino CNC project.

Please don't let me mislead you. This is a communication framework that allows your Arduino to link up to an opensource industry standard CNC host software. That way, all you have to do modify the sketch to make the motors move and read some inputs (like switches).

All the heavy lifting is already done for you, things like the gCode interpretation, gCode generation wizards, sample files, GUI, multi-Arduino communications, machine visualization, etc.

Its all opensource, free to the public.

So if your interested feel to check us out at http://emc2arduino.wordpress.com/.

Any questions?

Parallel ports are generally faster (provided you’re using a suitably fast PC).

Emc2Arduino is really meant for those that:
  1. Have no parallel port available. (Newer PC’s or Virtual Machines for example.)
  2. Have an existing CNC that needs expansion.
  3. Want to toy around with CNC’s (or even robotics) but without buying dedicated hardware.

PS. Sorry for the delay in response. (PC Upgrade complete.)

Dewy

Does it look like this one?
http://www.anf.nildram.co.uk/beebcontrol/arms/atlas/index.html

Looks like the gripper hold a cardboard sign pretty well. You could get some chuckles making it 'flag' messages with it. (Like "Wiley Coyote" from the road runner cartoons.)

A long time ago I saw some controllers that were similar in an old' school DIP-package auto-insertion machine that I had to nurse along from time to time. But I was just the night-shift operator of the machine and would read the tech manuals for it between cycles. I got to know that machine better than the maintenance crew did. In fact they unofficially called on me for light-duty repairs. (It was always wearing out a few segments of ribbon cable by flexing them to death.)

It sounds like you have the basis for a really killer toy CNC project.

I posted some files that allow people with an Arduino and a free copy of LinuxCNC to make there very own CNC machines. If your interested it can be found at http://emc2arduino.wordpress.com/

Emc2Arduino has been released! (As well as a new Homepage)

Added support for:

• Spindle control, On/Off, Direction, RPM control.
• Coolant options, flood and mist.
• Power Supply control.
• Power and E-Stop indicator output for LEDs and such.

Were accepting feature requests on our poll.
Cast your vote and be heard by the development team.

Come and check us out at http://emc2arduino.wordpress.com/

Emc2Arduino has been released! (As well as a new Homepage)

Added support for:

• Spindle control, On/Off, Direction, RPM control.
• Coolant options, flood and mist.
• Power Supply control.
• Power and E-Stop indicator output for LEDs and such.

Come and check it out at http://emc2arduino.wordpress.com/

Another option you could do is to add a 10 microfarad capacitor to the reset pin to keep the arduino from rebooting (unless you press and hold the button). That way your data flow would be as it would be over Bluetooth.

Or that the Arduino resets when you establish a serial link to it.
The delay just waits it out.

Yes, you can. In principal you have to play the motor's own inertia against it.

For example to get a stepper to accelerate smoothly:
1. Get it going at its base speed.
    Use only full steps for now. (microStepping + accel = tricky business).

2. Once motor is at speed, slowly increase the speed of step pulses.

3. Watch motor go faster and faster until you reach the supply voltage -vs- inductance barrier.
    (This barrier can be pushed with higher voltages.)

My quadstepper at 12volts driving nema23 steppers. Can start moving full steps at 100 Microseconds per pulse, and then (once already in motion) speed up to 2x speed by slowly shortening the pulse delay down to 50 Microseconds. But if i try to use the minimum 25 Microsecond rating from sparkfun's website to start with my motors will just sit and sing because I haven't given the run-up that they need to spin like that. (That and I myself need more voltage.)

If you need some code examples check out my stepMode() and stepLight() functions in my CNC controller project also posted here at: http://arduino.cc/forum/index.php?topic=92561.new;topicseen#new

Need a good sketch to some non-blocking stepper motor control over a serial link?

Maybe your looking for a full-featured interface for your Arduino controlled CNC machine.

Or you just want to build a RC robot complete treads and a 7-joint arm.

Well I'm glad to say that I have a sketch here to help you out!

If your into CNC stuff this is what EmcArduino can do for you:

  Directly supports LinuxCNC (EMC2.4/Axis). The free top-end CNC control software.
  Up to 9-axis simultaneous stepper motion control.
  Min/Max/Home limit switches for each axis (both physical and virtual supported).
  Support for E-Stop, Power, Stop, Start/Run, Pause, Resume and Program step buttons.
  Touch probe input for G38.x commands.
  Software selectable microStepping.
  Tuning LED indicator lets you get the maximum safe performance for YOUR application.
  Entirely USB based interface, no more printer cables required. (but still optional)
  Partial application support for those that just want an addon for their current rig.


If your into robotics:

  9 non-blocking stepper channels that won't hold up the show while ONE motor finishes moving.
  Serial command interface makes cross-platform building a breeze.
  Written with the native Arduino IDE for easy code modification.
  Uses the digitalFastWrite2 library for 8x speed over standard digitalWrite command.
  Software configurable mircoStepping for dynamic speed control.

And to top it all off:
  Its Open-Source software so it doesn't cost a thing!

Interested? Here's the link. http://emc2arduino.wordpress.com/

Hot off the presses, EmcArduino 06b CNC control has just been released.

Added support for the following:
  E-Stop
  Power
  Start/Run
  Stop
  Pause
  Resume
  Program step

Accepting feature requests, if you got one and its related just let me know.  

By the way, it also accepts basic serial commands which makes it an excellent robotics controller!

With 9 non-blocking stepper channels. That's enough to control an entire RC robot with an 7-joint arm to boot! Just feed it serial commands and go.

https://github.com/dewy721/EMC-2-Arduino
Enjoy!

EmcArduino_05b has been released.

Completely rewritten code, optimized, documented and cleaned up.
3 times faster than previous versions.
Full support for virtual and/or physical limit and homing switches.

Now supports full 9-axis (non-blocking) stepper motion control, expanded HAL file.

Included example ini file to get your CNC machine up and going fast.

Coders wanted.

https://github.com/dewy721/EMC-2-Arduino

Sorry about that I should have been more clear about it in the description.

In the HAL file you comment out the lines starting with "net" that refer to parport. This is normally the case, UNLESS you want to take input from the parallel port as well. But that would make for a debugging nightmare should something go wrong. (Limit/home switches for example.)

ie:
#net home-x <= parport.0.pin-10-in
#net home-y <= parport.0.pin-11-in
#net home-z <= parport.0.pin-12-in
#net home-a <= parport.0.pin-13-in

0.2b is the initial public release that has support for making 2.1-axis servo/encoder driven plotters. It just uses 2 moving axies (X,Y) and one solenoid (Z) to deploy a pen/pencil/marker with.

0.4a however has temporarily dropped servo support in favor of stepper control. This version controls four stepper motors simultaneously and was developed using an Arduino Mega2560 and a quadStepper controller from sparkfun. This makes a setting up a 3 or 4 axis CNC a lot easier.

When I get a chance It re-include servo/encoder support and mix-n-match so junk bot CNC building will be just another weekend mashup. I'm still looking for user input, coding help, and general feedback. So if you use it and need some doodad or feature I'll try to add that into a future release. Wanna help with the code? Just let me know.

I haven't seen one of those in a LONG-LONG time! It technically does have a DIR pin (tied to one of the step pins with a pull-up resistor). Its a Uni-Polar driver ** IF ** I recall correctly.

Sure, you can work with that.

Here's a (modified) non-blocking function I use to drive the steppers for my CNC project.
You can call it as often as you like, from your loop() routine. It does not block, and it uses the digitalFastWrite library for an 8x speed boost.

Code:

#include <digitalWriteFast.h> // http://code.google.com/p/digitalwritefast/

#define stepPin1a 2
#define stepPin1b 3
#define stepPin2a 4
#define stepPin2b 5 // Add more as needed.

int minStepTime=25; //delay in microSeconds between step pulses. lower=faster.

boolean stepState=LOW;
unsigned long stepTimeOld=0;
long stepper1Pos=0;
long stepper2Pos=0;
long stepper1Goto=0;
long stepper2Goto=0;

void stepLight()
{
  unsigned long curTime=micros();
  if(curTime - stepTimeOld >= (minStepTime/2))
  {
    stepState=!stepState;
    
    // Add more as needed here as well. (Must match #define section.)
    if(stepper1Pos > stepper1Goto) digitalWriteFast2(stepPin1a,stepState);stepper1Pos--;
    if(stepper1Pos < stepper1Goto) digitalWriteFast2(stepPin1b,stepState);stepper1Pos++;
    if(stepper2Pos > stepper2Goto) digitalWriteFast2(stepPin2a,stepState);stepper2Pos--;
    if(stepper2Pos < stepper2Goto) digitalWriteFast2(stepPin2b,stepState);stepper2Pos++;

    stepTimeOld=curTime;
  }
}

// call from loop routine like this:

void loop()
{
  stepper1Goto=12345; // update as often as you like.
  stepper2Goto=67890;
  stepLight();
}

That should do what you want, add 8 more entries top and bottom and you'll have all 6 steppers looking for thier long lost arm in no time at all. If this rusty old mechanic's memory serves me right. That should handle about 24v@5 amps per coil (WITH FAN) [120 watts total]. Nice score on the salvage btw!