Re: [CAD_CAM_EDM_DRO] Re: CAM Software Advice for Shopmaster CNC

Wayne C. Gramlich wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, John Dammeyer <johnd@...> wrote:
>
>>Hi Wayne,
>>
>>
>>>John:
>>>
>>>The buffer board with the PIC16F877 can generate a step
>>>every 20uSec. However, I'm not sure that there is any
>>>realistic way to ramp a stepper up to that speed. I
>>>think a step every 100uSec is a more realistically
>>>obtainable rate -- call it 10KHz step rate. It won't
>>>win any of the Inch/Min. derbies out there, but quite
>>>respectable for a table top machine.
>>>
>>
>>I have my ELS running a 10 uStep/Step at 20kHz which is
>>50uS per step maximum. It used to be 25kHz (40 uS) but
>>I just ran out of processor time since the interrupt
>>routine is also doing the micro-stepping support for
>>the LMD18245 drivers.
>
>
> These 8-bit micros are nice, but they sure do not seem
> to be increasing in speed very fast.
>

There are also chips from Atmel, NXP and others that have an
ARM7 CPU, flash memory, RAM, serial and Ethernet MAC on chip.
The chips run from $7 to 14 in low quantity, and there are some
off-brand demo boards for not much more than that ATmega board.
The chip maker's and dev system maker's demo boards are around
$100 - 150. These have a 10/100 Mbit Ethernet. You can get
128, 256 and even 512 KB of flash and 64 K or RAM on these.
They run 50 -72 MIPS on the ARM CPU. The ARM7 is a 32-bit CPU.

Jon