Idiot proofing my Bankstick 4x4?

[m00dawg]

So I think I am close to finishing my first board in EAGLE (holy crap the auto wire routing feature is awesome!) In this case, it's a multi-bankstick board. In this case, I wanted to have the option of putting the chips on the board itself or externally. So, the board has both for each bank, of which there are 8. I *think* the board is in relatively good shape, but figured it might be wise to see if someone might want to take a look? :) I'm a bit confused as to why EAGLE is looking at the bottom of the board (I assume that is the case anyway, since the text is backwards) so I'm a bit worried I may have done something there :)

This is one of the boards I wish were available from Smash, so if I can get this right, I think I'll be pretty happy. And, of course, I was going to give the EAGLE files out so others can potentially use these as well. If this board actually works, I was then going to make a C64 Optimized PSU board (which is probably going to be even simpler than this board).

bankstick-board.pdf

bankstick-schematic.pdf

bankstick.zip

[SLP]

I don't know why you need the external connectors.

Do you need them for external Banksticks?

In this case you only need 4 pins for each IC: +5V, GND, And the 2 data lines.

This could decrease the size of your board

edit: had a closer look. I think I know now what you're wanting to do.

[cimo]

-what are those vias at J0 doing?

-are you going to get this board done?

--there is some weirdness on those "Jx" texts

[nILS]

A couple of things:

* don't draw all the +5V, GND connection in the schematic - this just gets confusing. Use the ground and +5V symbols instead.

* don't put junctions everywhere. Only use those where they are needed. And that is only where more than 2 lines cross or intersect or touch and need to be connected.

* don't use the autorouter.

* do use a ground plane (search the forum for that)

If you want to you could have a look at the cleaned up version in the attachment. It's basically the same thing, I just removed some stuff from the schem to make it a bit easier to read and routed the board a bit neater (still not good, but a bit better). Maybe you find some of that inspiring.

bankstick_nils.zip

[lylehaze]

In my experience I can offer this gem of wisdom..

There is no such thing as "Idiot Proof". The idiots are much better at being stupid than we are at being smart.

So, assuming that "Idiot Proof" is impossible, perhaps the best we can hope for is "Moron Resistant" :-)

I use the autorouter in Eagle. I usually follow it with some manual route adjustments, but hey, it's free!

Have Fun,

LyleHaze

[m00dawg]

Thanks for all the help! I will definitely look at the ground plane (I assume the new board layout uses that, nILS?). I see a bit of a conflict over using the auto-router or not :) I haven't really figured out how to do it manually but I don't suppose it would be that difficult. I am still confused about the board view. It is looking at it from the bottom right? Which is why the text is backwards?

As far as the schematic, it too, makes things look much better. I used the junctions so much because I was getting warnings all over the place initially, but I now see what you're getting at. I didn't realize you could use the GND and V connections that way either :)

@SLP:

To elaborate a bit on the pins, it's an either/or setup. So you can use stuff the socket with a chip OR use the pin headers and route them to an external connection. That way you can use a mix of internal and external banksticks.

@cimo

I do plan on having the board printed. I have not looked at the costs, but I've heard it's pretty cheap to do these days and I would much rather have a real board over a protoboard where possible. I suppose we could try to figure out a bulk order if people want to go that route if that is what you were implying, but I don't know that I'm the best person to coordinate something like that, given that I still consider myself somewhat of a newb.

Anyways, I'll go ahead and make the changes and push another revision out here soon. And I like Moron Resistant. That should be on a shirt man!

[nILS]

I assume the new board layout uses that, nILS?

Correct.

It is looking at it from the bottom right?

No. You're looking down on the top side of the board.

Which is why the text is backwards?

Um. No :-) Blue = bottom = solder side, red = top = component side. You look at it from the top/component side, hence the blue text, which is on the bottom/solder side is mirrored.

I didn't realize you could use the GND and V connections that way either :)

There's much more to explore :-)

it's an either/or setup

What happens if you (accidentally) plug both in?

I do plan on having the board printed. I have not looked at the costs, but I've heard it's pretty cheap to do these days

~30€ gets you there. And a bit further.

edit: I wanted to add something and forgot. D'oh.

edit 2: Oh, I remembered - good use of tags, m00dawg :D

[Tanstaafl]

ahhh the joys of electronix

That was one of the first things my mentor showed me... back in the 60's.... he says, "Look at this schematic"  ... ( i don't remember what it was...)... and i say.. ok... i do.....

he points to some obscure point on the schematic, then traces his finger...... all the way over to the other side of the schematic...

I say... 'ok, and?'

he says, 'that is the same electrical point in a DC circuit'

Of course i said 'BS' or the equivalent, i was only 12 or 13.

but guess what? he was correct.... that cleared up schematics ... not really sure they had autorouting back then, but yes... turn autorouting off. Seems to work for me with Eagle.

gb

[stryd_one]

Just to balance things out, there are generally three schools of thought on autorouters:

1) They suck, don't use them

2) They suck, but on complex boards they can experiment with the layout faster than you ever could, so you can take a hint from it, and then rip it all up and do it manually - because autorouters suck, remember?

3) Who cares, just autoroute it

Given that this isn't a complex layout at all, 2) does not apply... And given that it's very simple, 3) is overkill.... leaves us with the generally accepted answer:

1) They suck, don't use them

Edit: and nils is right, that's how tagging works well :)

[m00dawg]

Woohoo! I finally got tags right :) In terms of the auto-router, I assume I then just need to layout traces myself? Is there a how-to on how to do this? I basically just ran the ratsnest tool, followed by the auto-router. Not sure how to do it any other way :)

No. You're looking down on the top side of the board.

Um. No :-) Blue = bottom = solder side, red = top = component side. You look at it from the top/component side, hence the blue text, which is on the bottom/solder side is mirrored.

That's weird because, when I set the text to be on the top, it was still backwards? Either way, I'll need to redo my board because I want the J0 header (the one that plugs into CORE) on the right. Not sure why. I just like it there :)

What happens if you (accidentally) plug both in?

Bad things I assume :) I thought about using jumpers, but I figured in a project like this, common sense would dictate not to try and use both. Granted, I can make the board smaller by doing away with the headers. I thought having bank 7 (or 6, depending on how you are counting :) as the external one and just have a header there. So there would be 7 on the board, 1 being for the ensembles if using this on a MidiBox-SID (which is where I plan on using it first).

[nILS]

That's weird because, when I set the text to be on the top, it was still backwards?

Text on the red/top layer should be the right way around. If you write text on the bottom layer and then use "change layer" to put it on the top layer this can happen though. Select the top layer first, then add the text.

[m00dawg]

Text on the red/top layer should be the right way around. If you write text on the bottom layer and then use "change layer" to put it on the top layer this can happen though. Select the top layer first, then add the text.

Awesome, I'll give that a shot hopefully today, or whenever I get to re-working this thing. I may rename it too. Bankstick 4x4 implies 16 sticks, when, in reality, it's just 8 :P I think I am going to use a header for only one of the banks though. I can't see a need to fill up all 8 banks internally and having the extra one would be convenient. That will also make the board simpler and smaller.

Thanks everyone for all the help! Again, I'll post updates once I have them in case anyone wants to make their own, change it for their own use, etc.

[bugfight]

4) Manual routing is for suckers

like any tool, if you don't know how to use it, maybe you shouldn't

[stryd_one]

4) Manual routing is for suckers

==

3) Who cares, just autoroute it

Actually I thought of you when I typed 3) :D

[bugfight]

==

Actually I thought of you when I typed 3) :D

well, the "who cares" part bothers me.

what exactly are we not caring about?

faik it's how pretty the pcb is.  in fact the "prettier" pcb may have real issues.

for example long parallel traces are generally bad, especially with high freq signals.

yet they appear frequently on manually routed pcbs.

otoh, if you don't input which signals need to be short, you can wind up with meandering clock lines etc...

it does take some work to tame the beast and maybe beginners should avoid it...

anywayz, you can go ahead and change to:

3) nobody should care how pretty it is, go ahead and use the autorouter.

[lylehaze]

OK, so I'll add a bit on the autorouter.

I agree that it can screw things up horribly.

Setting priorities properly can help that a bit.

Using a bit of common sense to arrange the parts on the board is the biggest part of getting it right. If your layout is wrong, your traces will be long.

So I use it to show me "what if" scenarios much faster than I can manually route anything. I rearrange parts, swap gates, whatever it takes to get the most sane autoroute I can get. Then I check every single trace to make sure it's not doing something completely stupid.

On a complex board like the channel board for the MBMixer, I might spend two weeks or more on a 4 square inch board, so it's not fair to say I'm ignoring it. :-) But that is a really tight layout, and being audio, it all matters.

I'm not sure I could have completed that board at that size without the autorouter, but there was a LOT of manual editing afterwards, mostly getting the ground plane to go everywhere.

In the end, it's whatever works for you. :-)

LyleHaze

[m00dawg]

Well, in this case, is the clock a big issue for the BandSticks? If not, it doesn't matter how long the wires are, no? Either way, the board's pretty simple so I'm pretty sure I can route things by hand this time around.

[stryd_one]

Correct :)

[m00dawg]

As promised, here's an update. I renamed it to MidoBox BSx8, although I guess it should be 7+1 or something (since one is meant to be external. Anyways, the wires are sort of ugly. I'll admit, I cheated a bit a used the auto-router and then moving things around manually. The result is, well, still ugly, but perahps less so. I also have a ground plane this time, as suggested.

Thoughts, Suggestions, Flames?

bankstick.zip

bankstick.pdf

[nILS]

for example long parallel traces are generally bad, especially with high freq signals.

* And the autorouter doesn't do that? Right.

* And the autorouter knows which signals are high freq? Right.

yet they appear frequently on manually routed pcbs.

* As they do on autorouted PCBs.

it does take some work to tame the beast and maybe beginners should avoid it...

You know how much I gerenally dislike the autorouter, but my main concern in this case is that a newbie start to autorouter having absolutely no idea what the result really is, or should mean to him, and simply assumes it's working and perfectly good as Eagle did it. So I'm pretty sure manually routing the first couple of boards will give a beginner a fairly good idea of how the whole thing comes together.

Again the same quote:

it does take some work to tame the beast and maybe beginners should avoid it...

Agreed. So eagle/kicad beginners: Please figure out how to manually route first, it'll save you from a lot of probems when you possibly start autorouting later on.

[bugfight]

* And the autorouter doesn't do that? Right.

* And the autorouter knows which signals are high freq? Right.

* As they do on autorouted PCBs.

wrong

You know how much I gerenally dislike the autorouter, but my main concern in this case is that a newbie start to autorouter having absolutely no idea what the result really is, or should mean to him, and simply assumes it's working and perfectly good as Eagle did it. So I'm pretty sure manually routing the first couple of boards will give a beginner a fairly good idea of how the whole thing comes together.

why assume n00b will correctly rout it manually then?

in either case you need a critical eye and some knowledge of drc and erc

Again the same quote:Agreed. So eagle/kicad beginners: Please figure out how to manually route first, it'll save you from a lot of probems when you possibly start autorouting later on.

agreed.  n00b should only attempt a simple pcb anywayz, and since this may be the only pcb he does, the time spent will be less than learning the autorouter.  and if there are more to come, then manual routing and learning to use drc and erc can give you a head start on taming the beast...

but this blanket dismissal of using autorouters is naive at best.

if you enjoy trace-tetris, go ahead, but otherwise there are ways to make it much easier if you are willing to learn.

i prefer to spend my time on other things.

(like sitting in the chat all day, etc)

[m00dawg]

Actually, I want to make at least one more board - for the C64 Optimized PSU, though that one is going to be even simpler (it's super simply on a protoboard anyway). I suppose I could have started with that one first...hmm...anyways.

So the consensus is to DIY before messing with the auto-router eh? I traced the paths and the auto-router appears to have done things the right way, although it does, indeed, look pretty ugly. I'm going to try making a board manually hopefully this weekend to compare. This circuit is simple enough I don't think it's going to be all that crazy.

I will say, however, I have WAY more respect for Wilba than before (and I already had respect for him :P). I have no idea how he was able to bust out his MB-6582 with one big board. This small tiny board has taken me more than a week now. Granted, while much of that is figuring out EAGLE, a larger board has to be an interesting affair indeed.

[nILS]

wrong

pfft.

edit: okay, to keep this post from being totally pointless, see attached picture, layout generated by autorouter. I see long parallel traces.

[bugfight]

pfft.

pblblblblblbt!

[stryd_one]

okay, to keep this post from being totally pointless, see attached picture, layout generated by autorouter. I see long parallel traces.

Perhaps you would be so kind as to suggest an alternative layout (manual) for the sake of demonstration?