54 October 2013
appropriate resistor across the CURRENT SET pins.
If our PC happens to be old enough to have a parallel
port, we could use the parallel port output pins to drive
the GECKODRIVE’s opto-isolated inputs. However, doing
so would require a hefty amount of programming at the
computer level. If we can’t program what we need, we
can throw money at the problem and purchase a fancy
PC CNC application.
Today’s PCs have dumped both the standard RS-232
port and the parallel printer port in favor of USB. USB
allows us to drive external devices at very high data rates.
However, do you see a USB portal on the GECKODRIVE?
Although USB is a robust data channel, applying USB to a
CNC application raises another possible computer-related
To perform efficiently as a CNC controller, the PC
must be equipped with enough resources (RAM, disk,
CPU, etc.) to quickly make the necessary calculations
required by the CNC application.
Purchasing a high-end super fast PC is not
the complete answer because we would
still have to provide an interface between
the PC USB portal and the
GECKODRIVE’s opto-isolated inputs. Since
we’re being forced to include an interface
board, let’s make it worth our while.
The DynoMotion KFLOP
The DynoMotion KFLOP shown in
Photo 2 augments a PC that is acting as a
The DynoMotion KFLOP can perform 32-bit and 64-
bit floating point math without the assistance of the
attached PC. Everything a CNC motor needs in life is part
of the KFLOP’s programming. The DynoMotion KFLOP
even comes with its very own C compiler. The USB
connection is simply a link to the KFLOP’s monitor and
control program that is running on the PC.
As you can see in Photo 2, there isn’t very much
KFLOP hardware to talk about. Don’t let that mislead you.
Connector JP7 (lower right of Photo 2) houses 18 LVTTL
I/O pins. There are 10 LVTTL I/O positions at JP4 (Aux #0)
and 10 more at JP6 (Aux #1). Nine more LVTTL I/O
positions are housed in the female RJ- 45 connector JP5
(upper right of Photo 2). JP2 is the JTAG interface. We
won’t be utilizing the services of JTAG here.
Now that you are aware of the DynoMotion KFLOP’s
resource-rich I/O subsystem, let’s put it through its paces.
All we need as a prerequisite for manipulating the KFLOP
I/O subsystem is a basic knowledge of C programming.
There are a bunch of I/O positions to keep up with.
Not to worry. The KMOTION IDE (Integrated
Development Environment) allows us to keep tabs on
every bit of the KFLOP I/O. KMOTION provides access to
the KFLOP C coding and hardware programming
environments. It is also possible to do some G code
■ Photo 2. The DynoMotion KFLOP is a
high powered embedded computing
device that is capable of running multiple
C subprograms (threads). The threads
directly affect the behavior of the
DynoMotion KFLOP's I/O subsystem.
■ Screenshot 1. This view allows us to write our C program,
compile it, and load it into temporary storage for execution.