Acorn Hardware Manual?

[drdennis]

I have gone through a lot of documents under the "ALL Acorn Documents" but have not stumbled upon anything documenting the actual Acorn board.
With my DIY hat on, I'd love to see the Acorn schematics, but I understand that it is not an open hardware platform, so that may be wishful thinking. But as an electrical engineer I'd like to see at least definitions and electrical characteristics of the board interface points, so I can stand behind the system I design.
Does such a document exist? This forum has tons of really useful info, but I could not see anything related to what I am looking for. Am I missing something?

I am looking for I/O electrical characteristics, or at least a functional description of the individual interface points. For example, as an EE looking at the example wiring diagrams I know that DR1 must be an open collector NPN driver output, but I would like to see that stated somewhere, possibly together with the electrical characteristics of that output (plus some description of how to control it).
Similarly, the H6 connector has signals labeled Output1 through Output5 -- what are those? Are they related (or connected) to any other interface points on the board? Obviously, a lot of this can be reverse-engineered, after all I have the board running, but I am hoping that there are some docs I have yet to discover. Thanks!
Cheers

[eng199]

https://www.centroidcnc.com/centroid_di ... manual.pdf

The hardware manual is inserted at page 94 of the manual in the link. That is probably close to what you are looking for.

[drdennis]

Thanks, I really appreciate the pointer; that's exactly what I was looking for. I looked at that document a couple times but unfortunately that section is missing from the index.
A couple things are missing there, but overall the Centroid folks have done an excellent job capturing what a typical engineer would need to be able to control something with Acorn.

[cnckeith]

Hi,

Please clarify what are you saying is missing? and we will add it.

for everyone reading....the Acorn spec manual is at the end of the installation manual. i'll update the index in the acorn manual to reflect this. Thanks.

[martyscncgarage]

Thanks, I really appreciate the pointer; that's exactly what I was looking for. I looked at that document a couple times but unfortunately that section is missing from the index.
A couple things are missing there, but overall the Centroid folks have done an excellent job capturing what a typical engineer would need to be able to control something with Acorn.

Dennis, all Acorn Documentation is here:
viewtopic.php?f=60&t=3397

[cnckeith]

I updated the Acorn Installation Manual Index reflect the fact that the Acorn Specification manual is also at the end of that document.
refresh your browser to see latest. https://www.centroidcnc.com/centroid_di ... manual.pdf

[drdennis]

Thank you! Really appreciated. That was my biggest obstacle; as I had said I went through all documents including this one multiple times but I missed it because I relied on the Index.

As far as anything else "missing", well, that's a difficult line to draw. Ideally, A set of proper schematics for the interfaces, including the actual components (so one can decide for example if an output transistor can drive the desired load) would be ideal. Many little examples like that -- something showing how the DB25 inputs are combined with the screw terminal inputs. Etc. But I understand well that only very few customers would really care, as the most common use case is likely to deploy more or less common hardware components, following the recommended wiring diagrams. That is, the focus being on converting a conventional machine to CNC, rather than exploring the controller capabilities (which is what I am doing -- having the Acorn connected to my own test hardware). A lot of questions I have can be trivially answered with a multimeter or oscilloscope, or with a few simple experiments. Last but not least, this forum is an excellent place to fill the remaining gaps (in addition to being able to access years of other people's machining/CNC experience). I am happy to get the info I got, and I am happy that the Centroid folks care.

I will ask my questions here if I get stuck, and you can decide whether or not the answer is worth capturing in the manual. Meanwhile I am thrilled with how far I got in the few weeks I've had the Acorn.
Cheers

[martyscncgarage]

Thank you! Really appreciated. That was my biggest obstacle; as I had said I went through all documents including this one multiple times but I missed it because I relied on the Index.

As far as anything else "missing", well, that's a difficult line to draw. Ideally, A set of proper schematics for the interfaces, including the actual components (so one can decide for example if an output transistor can drive the desired load) would be ideal. Many little examples like that -- something showing how the DB25 inputs are combined with the screw terminal inputs. Etc. But I understand well that only very few customers would really care, as the most common use case is likely to deploy more or less common hardware components, following the recommended wiring diagrams. That is, the focus being on converting a conventional machine to CNC, rather than exploring the controller capabilities (which is what I am doing -- having the Acorn connected to my own test hardware). A lot of questions I have can be trivially answered with a multimeter or oscilloscope, or with a few simple experiments. Last but not least, this forum is an excellent place to fill the remaining gaps (in addition to being able to access years of other people's machining/CNC experience). I am happy to get the info I got, and I am happy that the Centroid folks care.

I will ask my questions here if I get stuck, and you can decide whether or not the answer is worth capturing in the manual. Meanwhile I am thrilled with how far I got in the few weeks I've had the Acorn.
Cheers

Start a build thread. Give us details about your build. Well follow along. If you get stuck, post a fresh report when possible and provide as much detail about the issue and we'll try to provide suggestions.

Your right, it's nearly impossible to provide all the possible examples. It took several of us awhile to develop the Acorn Installation Manual. We knew it would at least get someone started and an overview with the process

Good luck with your build.
Marty

[eng199]

Ideally, A set of proper schematics for the interfaces, including the actual components (so one can decide for example if an output transistor can drive the desired load) would be ideal. Many little examples like that -- something showing how the DB25 inputs are combined with the screw terminal inputs.

The full set of schematics would be nice for a few people, but it causes some maintainability issues. For example, parts are very scarce right now. The ratings in the manual's charts are conservative. This allows room to substitute a wider variety of parts. If you design to the maximum capabilities of the transistor that is soldered on your ACORN, a future ACORN may not be compatible with your design.

The same DB25 and screw terminal input number should not be used concurrently. This is a similar case where Centroid is not going to guarantee that DB25 and screw terminal inputs interact in a particular way. I can tell you that DB25 and screw terminals were originally XOR'd together in hardware. After some hardware changes, the XOR function was moved to software to maintain compatibility. If you choose to use this feature, you have to accept that it may not work the same in future versions. The goal is to have long term support for the vast majority of features. Ideally, customers would not use configurations that are not recommended or documented. This allows the most flexibility to maintain and improve the advertised and recommended features in the future.

You are certainly welcome to explore the ACORN's capabilities. If you get too far off the beaten path, we may not be able to support you as well as we would like to.

[drdennis]

If you get too far off the beaten path, we may not be able to support you as well as we would like to.

Understood and 100% agreed.
To use a metaphor -- The more information on a tool I get, the better informed I will be to decide what I can really do with the tool. I do have the right to use my Dremel to trim my nails. But it would not be reasonable for me to ask the Dremel Customer Support how to do it, nor would it make any sense to complain to them if I ended with one of my fingers a bit shorter.
Cheers