Re: EHP External Hardware Proposal

Looks like I kicked off a hot topic. Good,

First, will a few of you PLEASE, PLEASE stop including every part of a
message in your reply. The use of quoting to establish a reference is
very good, but getting the full text of several messages 4 and 5 levels
deep, including that damn ad from One List at the bottom of every one is
getting annoying. And sad to say two of the worst offenders are Dan M
and hansw, two of the most prolific writers.

Ok, back to the subject.

What I would like to see develop is a serial protocol that was
independent of the final drive circuit- if we can get the right protocol
then you can choose to put steppers or servos or trained monkeys behind
it. What I want to do is separate the graphical and control part from
the actual motor movement.

In my specific case I like to use VB (even thought Im a linux user) to
do the gui stff, but want the black box to do the motor moves and timing
critial stuff that VB cant do. Yes, INDEXER-LPT can do this, and I have
a copy of it, but if I want to sell my program I dont want to have to
also sell a $300+ INDEXER-LPT

I have alread done this with a Tiny Tiger micro. I uses a very ascii
like command set, and does the bresenhans algorithym in the micro. I
send it a command like
G 100 100 200
and it moves the x motor 100 steps, the Y 100 and Z 200, in a
coordinated move, with appropriate ramping and timing. So far I have the
timing compiled into the micro, but it would be a simple matter to send
some init commands to set various parameters.

I have not yet done circular interpolation in the micro, but I dont see
any reason (other than time to do it) I cant.

I have looked at a few of the pages people have suggested here and will
go back and study them, but it is clear many people have developed their
own serial command set and none of them are compatiable. Can we solve
that, at least in the case of a command set suitable for a CNC machine?
Maybe INDEXER-LPT commands would be the ones to use? Then someone with
software written to use it could just let the commands go to a real
serial port instead of the INDEXER driver.

Can we separate the hardware part from the software protocol- lets try
to hammer out a serial command set that could drive either steppers or
serial, then let a couple other teams go off and design and build
hardware.

--
Ron Ginger
my web page is now at http://plsntcov.8m.com please update any links to
the old Ultranet site.