Re: EHP External Hardware Proposal

Reply from Carlos Guillermo between text:

> From: Ron Ginger <ginger@...>
>
> 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

Ron - I, for one, would GLADLY pay $300 for the beautifully choreographed
signals that IndexerLPT sends out the parallel port, but ONLY if I could
also find a nice windows CNC interpreter/frontend for it, for which I would
also GLADLY pay an additional up to $300. This combo could provide much
better performance than the equivalent external box such as Flashcut, and
they are charging over $1000 for their "no-upgrade" solution. To perform
the same lookahead and ramping that IndexerLPT handles in an external box
seems impractical and very difficult to me, especially for the price. Plus,
Flashcut's steprate is limited to 7300 steps/sec (in good weather) compared
to Indexer's 100,000+.

>
> 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.

Isn't the Tiny Tiger a pricey module??

> 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.

Please, please, use IndexerLPT commands in your VB frontend?! Then we could
have the choice whether we send them out to the serial port or write them
out to IndexerLPT.

> 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.

There we are... let's copy Indexer's command set! They've got it all worked
out, and they couldn't complain if it meant more sales of IndexerLPT.

> --
> Ron Ginger