Group Picstep pcb buy

[dberndt]

Well I've looked at the picstep board some more and I'm not real impressed with it I guess. Im not big on the fact that its actually 2 seperate boards.

The cnc4pc board isn't fully opto isolated, so I dont really know what the point is. Only the inputs seem to be isolated, I'd think that the outputs are probably just as prone to failure as the inputs and a parallel port with blown outputs is just as useless as one with dead inputs. So all in all I dont see the advantage to this board either. I'm no electrical genius so maybe I'm wrong here, but thats my current thinking.

campbell designs break out board looks to be pretty sweet and has lots of cool little extra features, this is the way I'm leaning currently, though its really expensive.

[Garfield2]

Well I've looked at the picstep board some more and I'm not real impressed with it I guess. Im not big on the fact that its actually 2 seperate boards.

Thanks for the support.

The reason I made it two boards was to keep it small, and also I have needs for only the output board without any inputs. It's nice to be able to seperate the two halves if needs be. Given the number of components involved and the need for seperate power supplys for the PC and the driver side it made more sense to make them into individual boards.

Alan.

[dberndt]

hey! No problem, any time you need a literary blow to the mean bean machine just let me know.

But seriously, I'm sure it works well and all, but I'd prefer it all on one pcb. Also a breakout board, unlike a driver is a bit more within the realms of what I can make myself, I've done some work with buffers and opto-isolators before and could probably put something together myself with a spare breadboard or perfboard and the parts I have kicking around without killing off too many brain cells.

I really can't say enough how much I appreciate work like the picstep boards Alan, its great stuff and its awesome that you've gpl'd it. Great work supplying all the files in a neat and thorough manner, supporting it here, etc, etc. Without your design I'm sure many of us would still be sitting at stage 0 thinking about cnc instead of trying to do it.

[ranman]

I would prefer a single board BOB design as well.
Alan - That is nothing against your BOB design.

Just a preference on my part - like your pref for splitting it up into multi-boards.

In addition to the two boards I listed:
I may even consider a DIY BOB using a breadboard or perfboard as well.

The Campbell board ($137.50 USD shipped) is out of the question for me.
Atleast for now.

I have a few spare Parallel PCI cards that I picked up on clearance that I am going to use - so opto is not a huge deal to start with.

Here is another simple board from Phils site: http://pminmo.com/4axis/4axisinterface.htm

I think there's an Opto board on there too - maybe Phill can shed some light on the boards on his site.

[pminmo]

Ranman,
The 4 axis board is/isn't compatable with the PICstep board. How's that for a political answer.
It isn't, in that a standard 10 pin IDC ribbon cable won't connect correct signals to the PICstep board. It is in that you could hardwire or use polirized connectors and discrete wire to a PICstep board. Which I plan to do to show the interoperability of modular designs, support the PICstep design as I think it is a good one, plus I have one stepper myself that I want to use on a project that is more than the 3977 can provide.

As for a opto board, I have a 3 axis single sided that a DIYer could do ready to upload to my website. It's not been built, I haven't gathered the documentation together.

Maybe we could all gang up on Allen and ask him to do a version of the PICstep board that is IDC compatable with the other 6 plus Open Source Boards.

Phil

[ranman]

I really don't want to gang up on Alan ...
I don't want him to feel like we're trying to

If he wants to modify the PICStep to match the other Open souce IDC pin-outs, I know that it would be appreciated by future users/builders of the board.
Too late for the boards we are getting - but would be nice for others.

I would like to see the 3 axis your working on - When do you think it may make it online?
If it looks doable for my budget/skill/time restraints, maybe I will go that route over the other two boards I was considering.

In regards to the CNC4PC board:
Even though it has Opto-isolated inputs -
How big of a concern should not having opto isolation be for the output pins, considering the output pins are buffered?

Quote from the prod. page:
"• Opto-isolated inputs. Isolates input connections to protect your computer from short circuits.

• Buffered outputs. Outputs are buffered through integrated circuits, allowing the card to output the signals without using the power from the parallel port.
"

Any info is welcome

[pminmo]

ranman,
I meant gang up on Allen in a nice way. As I have said a number of places, I think the PICstep board is a really good board. The Opto board is now on the website. I haven't put a part number in for the opto isolators, as there are a number that are pinout and spec compatible. Brian here on the Zone did most of the work, I did a little cleanup, but the man's got to be an artist, single sided no jumpers!

Phil

[ranman]

I knew what you meant by ganging up on Alan ... let him know how much it would probably be appreciated.
I also saw where you were sure to mention that you like his design of the PICStep.

But figured he could use a short break before we jumped him

Thanks for getting the Opto board online so fast.
I'll take a look at it later this evening (I hope I have time too).

[Garfield2]

Maybe we could all gang up on Allen and ask him to do a version of the PICstep board that is IDC compatable with the other 6 plus Open Source Boards.

Phil

Perhaps I could do this. I like the every odd pin being a ground because it increases the ribbons noise immunity. I'm thinking if I put the mode selection jumpers on the PICStep driver boards rather than the BOB, and put the enable line on pin 1 as per your schematic it could be done.

So :-

1 - Enable
3 - Direction
5 - Step
9 - +5V
2,4,6,7,8,10 - GND

Correct?

Alan.

[pminmo]

Alan, yes thats correct, Pin 9 we've tried to make flexible/multiuse on the +5. i.e. if there is a very low 5V requirement on the motor driver, the interface board can supply it. If the motor driver has it's own, one of the motor drivers can source the interface board. Also for opto isolation, the motor driver can power the output section of the isolator. Would be great to have your board work with the others!

Phil

[dberndt]

Well, Its been a week since they sent an email saying that my order has been processed and will be ready in a week. So I emailed them for an update, and hopefully a package tracking number and I got the same canned response, order processed, ready in a week. Hopefully its just the sales guy being misinformed because I'm not impressed with a 2+ week turn around.

[pminmo]

dberndt,
Their shipping is SLOW, my orders take almost 2 weeks from the postmark date.

Phil