Testing the waters...

Hi all,

For those of you who don't know me, I'm the guy who
designed the DRO board that Dan Mauch sells. I've
been very inactive on the group (and otherwise) for
better than a year now. Well, my son is now just
over a year old, and I'm getting the itch to get
back to the hobby. Anyway...

I've been casting around for a small project to work
on, and I've decided to try to take the DRO board to
the next level. Rewriting the interface is on the
list, but I've got to teach myself Visual C++ first,
so that's off in the future somewhat. Instead, I
was thinking about adding either some DAC output or
step/direction generation capability to the board.
Does this interest anyone?

TI/Burr-Brown makes a really sweet 4 channel, 12 bit
DAC with an 8 bit parallel interface and integral
voltage reference, which makes it nearly a drop-in
to the DRO board. Even better, Digikey sells 'em
for around $30. It's even a 28 pin DIP, so
depending on the exact pinout, it might be a perfect
replacement. Still, I'd rather add it to the 4-axis
board and add appropriate isolation. Quad
output/input turns the DRO board into a dirt cheap
servo controller, assuming we can get EMC talking to
the board.

OTOH, most folks use steppers. Maybe step/direction
is the way to go. I haven't yet investigated this
route, but maybe a simple 8255 chip would work. I'd
have to hook the output up to a scope to be certain.
No matter what, I'm sure I could implement this just
as easily as DAC output.

I'll warn you at the outset, this isn't something
that's going to happen overnight. My time is still
limited. But I'm hell-bent to get active again, and
this project seems small enough, and also something
I could do without spending too much money. And for
those of you helping Marty with his Series I BP
upgrade, you can blame him for getting me moving
again. The day he told me about the mill, my mind
wouldn't let me stop thinking about getting myself
involved with the group again. Thanks, Marty. :)

So, what do you guys think? It makes no difference
to me, as my interest is more in the building than
in the use of the board. Either way, I'm still
having fun.

-Tom Kulaga

P.S. I just had a thought: 4 DAC channels means 3
servo axes, and a spare signal that could be used to
control a VFD. Does that seem more valuable/useful?