Stepper Driver v1.1 - Sync wires between boards

I'm a little unclear on how you connect the SYNC wires between boards.

Reference, this wiring diagram: [farm3.static.flickr.com]

Do all 3 get tied together? Is only one of the pads (wires) used or do you use two?

Thanks.

Edited 1 time(s). Last edit at 12/23/2007 08:36PM by RoundSparrow.

Ok, I just tested with my multimeter and determined that on the PCB the two SYNC pads are connected So I'm assuming that it is really just one wire...

So I assume you wire like:

A ---> B <--- C

Where on the center of the three boards,the two pads act as a meeting point (hub) to the other two boards.

Edited 1 time(s). Last edit at 12/22/2007 10:04PM by RoundSparrow.

No if you look at the schematic they are not connected together they go to separate pins on the PIC.

I think you connect all the pins 1s together and all the pin 2s together. I.e. run 2 wires to all three boards.

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[www.hydraraptor.blogspot.com]

nophead is correct: Wire Pin 1 on all Stepper Controller boards together.

Pin 2 is not currently used by the firmware, but that is about to change,
so I suggest wiring all the Pin 2's together also :-)

Pin1 and Pin 2 of the sync connector should *not* be connected together.

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Jonathan

I'll rewire... i wonder why my continuity showed them bridged (this was before soldering anything on these pads), I'll test all 3 boards when I rework.

Zach: I suggest the wiring diagram should depict the two separate sync wires instead of showing it as a single wire.

Edited 1 time(s). Last edit at 12/26/2007 10:46AM by RoundSparrow.

Ok, I just confirmed on all 3 of my boards, which Zach assembled one of them... and I get 0.1 ohm resistance (continuity) between SYNC/SYNC on the same board.

These SYNC connectors don't even have different names.

Are we sure we are talking the SAME board here?

1: Stepper Motor Controller Card - v1.2
2: Stepper Motor Driver v1.1 (Arduino)

I am specifically referring to the "Driver" not "Controller". This is next-gen Arduino board I'm talking about.

Edited 1 time(s). Last edit at 12/26/2007 11:07AM by RoundSparrow.

No Jonathan and I are both talking about the official boards, sorry. Looks like Zach has moved to one sync wire. Best ask Zach!

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[www.hydraraptor.blogspot.com]

Sorry for any confusion.

Zach's boards are *Zach's* -- they are an unofficial side project experiment, and they are not (at least not yet) Reprap. It might be less confusing to use the "Electronics - Off Topic" forum when discussing them, leaving the primary "Electronics" forum for the official Reprap electronics?? Or if there is a need, we could create a forum just for Zach's electronics?

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Jonathan

Jonathan - The who, what, where, when are very apparent. I guess my question is WHY? Why is the design for a stepper motor controller using a pic and discrete parts when there are about 10 different chip designs out there for driving stepper motors? The chip designs end up being cheaper because they are a very common item and industry has been using them for over 20 years. They are also very simple because the manufactures have provided application notes on how to use them. Also I can take Zach's boards and put a parallel interface board in front of them and use them as is with EMC2 software and create CNC machines very easily. The larger the base of usage of a part the lower the cost. And I do believe that is what we are all after. If the board wishes to separate Zach's work ( which I find very helpful and I am build one of these myself ) then please bring into existence the necessary structure on the site and forums to isolate this work because I find that I want a reprap/repstrap NOW not 2 months from now. Jonathan - I think that you also will find that there will be difference between repraps. One of the main differences will be the materials that these are made of because in the United States it is easier to find threaded rod and screws and such in inches and not millimeters. Does this mean that if I build a unit using US parts and not metric parts that I won't have a reprap? ( Sorry about the rant ) Please setup the changes so that Zach's work can be found easily and I bet we can all get to where we want to be in the end.

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Bob Teeter
"What Box?"

bobt wrote:

> Jonathan - The who, what, where, when are very apparent.

Well, if it was *that* apparent, we'd not have had confusion in this thread about which set of boards was being discussed :-) Nophead and I both made the same mistake, so it wasn't just me having a "senior moment"!

> I guess my question is WHY?

I'm not an electronics design wizard, and I know nothing much about CNC. The Reprap boards already existed when I joined the project. Reprap Darwin is proceeding towards an initial v1.0 release. Slower than many of us would like, but it is headed in the right direction and remains on target for a 2008 release date. Its current electronics get the job done now -- they work. Like quite a few others, I have built and tested them. Redoing them now doesn't seem to me to get us towards v1.0 any faster. The core team is small, all volunteer, and several of us have only limited time to work on Reprap. There are other things (software packaging, a couple of firmware changes, support extrusion stuff, ...) that are necessary before v1.0, and those things have priority over other changes at this point.

> Also I can take Zach's boards and put a
> parallel interface board in front of them and use
> them as is with EMC2 software and create CNC
> machines very easily.

Cool! But that is not the current goal of the Reprap project! Go for it, if that is what you want to do. But realize that it perhaps isn't directly helping this project along to do so. How will your work in doing that help the Reprap project reach its goals?

> If the
> board wishes to separate Zach's work ( which I
> find very helpful and I am build one of these
> myself ) then please bring into existence the
> necessary structure on the site and forums to
> isolate this work because I find that I want a
> reprap/repstrap NOW not 2 months from now.

I'm not on the RRRF board. I don't have the power to create forums here (I have some limited moderator/admin powers on some forums here, or at least, I did until the forums were renamed/restructured recently!). Also, Reprap is a research project, so it is not necessarily directly aiming at getting bobt what bobt wants super-fast :-)

> ... in the United States it is easier to find threaded
> rod and screws and such in inches and not millimeters.

Grin! That discussion has happened before. More than once!

I'm living in the USA, and so I feel that pain too. But I believe the universality of a design that can be used (replicated!) worldwide is worth some work having to hunt down metric parts for those of us in the USA. Apparently, you don't feel that it is worth it. OK. It all depends on what your goals are. Getting "something that works to make stuff with right now, in less than a couple of months" is not my goal, nor is that the stated goal of the Reprap project.

> Does this mean that if I build a unit using US parts and not
> metric parts that I won't have a reprap?

Probably, yes, in my personal opinion :-) You'd have a Repstrap, maybe. You most likely wouldn't have a Reprap Darwin, I think I can say with some level of confidence. I don't think non-metric parts will fit well into the Darwin RP components anyway. Are you planning to redesign them all to use US-style thread and bolt sizes etc.? And then get those non-metric parts commercially RP-ed for you? That's quite a lot of work in AoI, and significant commercial RP cost -- probably rather more work and cost than finding metric hardware over here!!

Once v1.0 is out, that kind of local evolution of the Reprap design is expected and welcome. But for right now, the core team doesn't have the resources to do it!

> Please setup the changes so that
> Zach's work can be found easily and I bet we can
> all get to where we want to be in the end.

I expect we can release Reprap v1.0 during 2008, which is a stated project goal. Whether you can get yourself a working repstrap in less than a couple of months is a very different question, I don't want to bet on that :-)

I don't have the power on these forums to create a new forum; I've made a suggestion here, that's all. I do think that it would reduce confusion to have discussion of Zach's electronics kept separate from discussion of the Reprap electronics, as this thread has just proved :-)

Let's be clear: I think Zach's work is cool, and it looks promising. But for right now, as far as I am aware, his stuff is not officially Reprap electronics. (That may well change in the future, who knows? I've recently been encouraging him to make it closer to 100% compatible with the Reprap host code...). For now, I think we should keep discussion of his boards clearly separated from discussion of the Reprap electronics, to avoid the kind of confusion just experienced first-hand.

Jonathan

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Jonathan

Hey Guys,

arduino vs pic drama aside, here is the answer:

first, there is a section on 'interface' on the wiki that explains how they are hooked up: [www.reprap.org]

the sync lines are from the L297 datasheet. unfortunately it is rather unclear on there as well. they are supposed to be used when you are using more than one L297. basically, i've just been making one stepper a master, and hooking the sync lines up to that. they deal with pulse generation.

to be honest, i dont think they really do much. i've run each stepper board as a master with no sync lines connected and there was no apparent difference. since each board contains its own pulse generator, they are sort of redundant. i left them on there because the reference design called for it, but i havent had any problems with running them without them connected.

try both and let me know how it works for you!