There are GCode interpreters for AVR, PIC and ARM devices already. Just
Google them. But most commercial packages use the PC software to convert
Gcode to step commands (Mach 3, KCAM, EMC2, TURBO CNC) and send the step
commands to dumb (by comparison) power amplifiers/drivers. Usually just
logic for motor control.
On Wed, Jun 27, 2012 at 12:22 PM, David Mitchell <gossiphog@...>wrote:
> This was one of my original ideas, perhaps to port GRBL (which runs on a
> very similar AVR chip) to the Cricut's hardware.
>
> http://dank.bengler.no/-/page/show/5473_connectinggrbl
>
> The biggest issue would be that GRBL outputs step/direction pulses, so to
> run this on a Cricut we'd need to just adapt this to the proper stepper
> phases.
>
> The Cricut hardware provides "half power" and "full power" control for each
> stepper phase, there are not enough PWM channels to do true sinusoidal
> stepping in both X and Y directions, but I rather like the "High Torque
> Half Stepping" mode described here:
>
> http://www.piclist.com/techref/io/stepper/linistep/halfstep.htm
>
> Flow control would still be an issue since there's not enough onboard
> memory to buffer more than the smallest jobs, but I think you could
> probably design a RAM card for the cartridge slot, or even a flashcard
> reader to completely cut the cord.
>
> Interestingly enough, Cricut cartridges contain their own ATMEGA16
> processor and 1 mbit flash memory (and a conveniently located programming
> header), I bet you could even reprogram one to serve as the job buffer, no
> hardware design needed.
>
> -David
>
>
>
> On Wed, Jun 27, 2012 at 2:04 PM, James <jamesrsweet@...> wrote:
>
> > ∗∗
> >
> >
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com, Randall Morgan <rmorgan62@...>
> > wrote:
> > >
> > > No, what I am describing is sending the step data not the GCode which
> has
> > > to be interpreted and compiled into step commands. It can be done
> using a
> > > RTOS but under a non RTOS it requires either extra hardware buffering.
> > >
> >
> > I rather like the idea of using Gcode since it's so ubiquitous in the
> > world of CNC. Seems like some of the modern microcontrollers ought to
> have
> > more than enough power to interpret Gcode and drive some stepper motors
> or
> > servos. It has struck me a number of times that in virtually everything I
> > have ever built with a microcontroller, even the lowest end ones end up
> > spending 90% of their time in delay loops.
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>
>
>
> ------------------------------------
>
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>
>
>
>
--
If you ask me if it can be done. The answer is YES, it can always be done.
The correct questions however are... What will it cost, and how long will
it take?
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