RE: Adding a DAC, DRO wrapping

[Charly Brauer <cbrauer-at-voyager.net>]

Hi Eric

I don't have code for ADMC401, nor do I have the development board.  I do
have a ez-kit lite for the adsp2181($90) and the c-compiler.  Before the
"BDI", I was working with this chip and rewrote a bresenham algorithm (2d)
to drive 2 stepper motors.  This worked quite well, better even than emc.
The motors seemed to have all of thier power and did not exibit any strange
behavior... but there was(is) the problem of getting info to the chip.
(And no GUI, or nice NC interp.) The chip has a dma port and I had that
working for a while to the ISA buss, but alas I lost it.  The chip doesn't
have a real uart, but Analog Devices implimented one in software .  I
downloaded it and got it running, except it uses some of the dedicated c
compiler registers.  So far I have not figured out how to do put the two
programs together.  I'd like to thou, because one of my applications uses
zillions of small moves and this dsp does them very well.

Anyway any of this code you can have.  Email me personally:
cbrauer-at-voyager.net.

As for emc and these dsp's, emc code makes me want to scream.  I find long
c and c++ programs difficult to read.  A satement like:
some_structure_defined_who_knows_where mystruct;... well now let's see
which one of these 30 *.h files is that defined in.  And makefiles, I can't
understand those hardly at all(unless they are very simple).

So I guess what I am saying here, is until someone writes code that is
understandable for "BDI", new hardware(from me) is out of the question.

I'd like to see it even in the emc.ini file:  	EMC_TASK = CUSTOM...
ADDRESS=0x300
... AXIS_0_OUT_FROM_CUBIC_SPINE=   ... AXIS_0_ADC= ... AXIS_0_ENCODER= ...
all the necessary paramaters.

One other thing, I've seen encoders readers implimented as "state machines"
on even lowly pic's.  

Also the ADMC401, problably could drive large AC motors that control
machine spindles(to close the loop) with out any costly modifications,
except of course some large MOSFET's.

At the risk of being "BDI"... and everybody knowing it!

charly        





    

At 09:21 AM 5/30/01 -0400, you wrote:
>
>
>Charly wrote:
>
>My personal dream would be a chip like ADMC401(see attach.).  This motor
>control chip has a encoder and pwm and dac plus can run almost any motor
>made even ac.
>
>So yes include code.  If noone else wants it, I sure do.
>
>---
>I also would like to use the ADMC401.  It has output as pwm, and
>high quality A/D converters.  The only thing that I am not happy about
>is that it only has one encoder interface per chip.  TI has a chip with
>two encoder interfaces, but I forget which model.  The entry price for
>TI is a lot more though: a minimum $1000 investment vs. free download from
>AD.  I was looking at the smaller chips AD makes, which don't have encoder
>interfaces, like the F327.  Those chips have very similar I/O to the ADMC401
> without the encoder or parallel interface, but the pin count goes down from
>144 pins to 28.  That seems a lot more hobbist friendly.  The cool thing
>about these chips is the ability to drive motors with very little extra
>circuitry.
>
>
>As far as the emc wrapper code, emcmot is the wrapper, and stg is a very
>good starting place.  The real problem is adding your code into the make
>files
>
>
>
>