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Offline lensdigital

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TopRouter bug?
« on: August 24, 2016, 11:15:03 AM »
It's been bugging me for quite some time, so I thought I would ask here.
In Eagle (any version since 7 or whenever TopRouter was introduced) frequently TopRouter reaches 100% and then goes down to 98% or something like that... And it ends with incomplete route. That's not the worse part, I understand Autorouter can't always route everything, except there are at least 7-8 variants that completed at 100%!
And they are quite usable too.
Also in some cases when TopRouter did complete 100%, it has much more Vias than other variants.
Anybody knows why that might be? :)
I haven't seen anyone mentioning it anywhere, but I can't be the only one who sees this issue...
 

Offline Karel

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Re: TopRouter bug?
« Reply #1 on: August 24, 2016, 04:34:41 PM »
I haven't seen anyone mentioning it anywhere, but I can't be the only one who sees this issue...

Because almost nobody use an autorouter. The human brain does a much better job in routing.
The difference between theory and practice is less in theory than
the difference between theory and practice in practice.
Expensive tools cannot compensate for lack of experience.
 

Offline lensdigital

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Re: TopRouter bug?
« Reply #2 on: August 24, 2016, 11:24:06 PM »

Because almost nobody use an autorouter. The human brain does a much better job in routing.
I'm sure a lot of people use Autorouter, especially for complex stuff.  I can't do very complex board by hand. Like the one attached for example. I would go insane if I tried to trace it for sure :)

 

Offline jgarc063

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Re: TopRouter bug?
« Reply #3 on: September 01, 2016, 04:37:24 AM »
It's been bugging me for quite some time, so I thought I would ask here.
In Eagle (any version since 7 or whenever TopRouter was introduced) frequently TopRouter reaches 100% and then goes down to 98% or something like that... And it ends with incomplete route. That's not the worse part, I understand Autorouter can't always route everything, except there are at least 7-8 variants that completed at 100%!
And they are quite usable too.
Also in some cases when TopRouter did complete 100%, it has much more Vias than other variants.
Anybody knows why that might be? :)
I haven't seen anyone mentioning it anywhere, but I can't be the only one who sees this issue...

Hi Lens,

I hope you're having a good day. The issue you are seeing can actually happen with any of the autorouter runs not only the toprouter. Usually the percentage drops because polygons get broken and you get a few extra airwires.

It entirely possible that a run other than the toprouter generates a result that you consider optimal. The toprouter variant is there to produce another alternative route. In theory topological routers should always produce better results than grid based routers but in practice that isn't always the case.

The same happens with the vias, most of the time the toprouter will produce a result that has fewer vias than the other variants but that isn't a hard guarantee.

hth,
Jorge Garcia
Cadsoft Support
 
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Online wraper

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Re: TopRouter bug?
« Reply #4 on: September 01, 2016, 05:08:34 AM »
I would go insane if I tried to trace it for sure :)
Insane is what on the picture. It's not complicated board. Also, the length of the traces is because of stupid component allocation.
 

Offline lensdigital

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Re: TopRouter bug?
« Reply #5 on: September 01, 2016, 06:52:28 AM »

Hi Lens,

I hope you're having a good day. The issue you are seeing can actually happen with any of the autorouter runs not only the toprouter. Usually the percentage drops because polygons get broken and you get a few extra airwires.

It entirely possible that a run other than the toprouter generates a result that you consider optimal. The toprouter variant is there to produce another alternative route. In theory topological routers should always produce better results than grid based routers but in practice that isn't always the case.

The same happens with the vias, most of the time the toprouter will produce a result that has fewer vias than the other variants but that isn't a hard guarantee.

hth,
Jorge Garcia
Cadsoft Support
Thanks for the info Jorge!  Yeah I understand that this can happen with any routes, I was just surprised that Top Router will allow routes that are not 100% to be selected.  Since I don't know set of logic rules it uses, I just assumed that #1 would be 100% completion, then maybe #2 least number of vias and so on...  I mean without 100% traces run board would be completely useless (and thus not optimal in any way) so it would make logical sense to make it a first priority :)


Insane is what on the picture. It's not complicated board. Also, the length of the traces is because of stupid component allocation.
But you don't know what components I'm using  ;)
These are 8x8 LED matrix blocks and there's 8 of them (3x8 rows of pins in each matrix). Driver ICs cannot fit anywhere else and my top priority was to make board as small a possible. In fact this is probably the best component allocation possible within board dimension and components selected. And guess what? It works just great!  I use autorouter on all of my designs with great success, and only once it failed me (HV power source).

« Last Edit: September 01, 2016, 06:55:30 AM by lensdigital »
 

Offline ReneK

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Re: TopRouter bug?
« Reply #6 on: September 02, 2016, 12:25:16 AM »
Hi Jorge!

Usually the percentage drops because polygons get broken and you get a few extra airwires.
Please take a look at CadSoft's guided tour, part 11:


You'll see a board that can't be simpler than that. The TopRouter reaches 100%, drops to 97.4% and ends with 94.9%. I can't see any polygon here, so what kind of "broken polygons" did you mean?

Beside that, the video also demonstrates that the TopRouter does not produce fewer vias. Variant 3 produces the same via count, but it got the job done!
 
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Offline lensdigital

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Re: TopRouter bug?
« Reply #7 on: September 02, 2016, 12:33:45 AM »
Thanks ReneK!  At least I'm not not the only one who sees this issue and think is OBVIOUSLY a bug :)  I'm not crazy!!! :)
 

Offline jgarc063

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Re: TopRouter bug?
« Reply #8 on: September 03, 2016, 04:02:33 AM »
Hi Jorge!

Usually the percentage drops because polygons get broken and you get a few extra airwires.
Please take a look at CadSoft's guided tour, part 11:


You'll see a board that can't be simpler than that. The TopRouter reaches 100%, drops to 97.4% and ends with 94.9%. I can't see any polygon here, so what kind of "broken polygons" did you mean?

Beside that, the video also demonstrates that the TopRouter does not produce fewer vias. Variant 3 produces the same via count, but it got the job done!

Hi ReneK,

Thanks for embedding the video I made. Need to learn how to do that.

I need to be more specific when I write. In the case of that video, you are correct there are no polygons so the broken polygons wouldn't be the cause for the drop in percentage here. In that video the blame lies with the optimize runs. The goal of the optimize runs is to minimize the number of vias and in that process it ended up sacrificing reaching 100% complete routing.

The solution would be to disable the optimize runs for the TopRouter. You can do this by clicking on the top router variant and then clicking on the >> at the bottom. This will expose the cost factors for the top router. Go to each of the optimize tabs and uncheck the active checkbox to disable them. That will avoid the autorouter trading off vias for 100% completion.

As to the vias, notice that I said most of the time. There are no hard guarantees so it's entirely possible for another variant to have fewer vias in its result.

hth,
Jorge Garcia
Cadsoft Computer.
 

Offline ReneK

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Re: TopRouter bug?
« Reply #9 on: September 03, 2016, 06:21:23 PM »
The solution would be to disable the optimize runs for the TopRouter.
Oh dear, why is "optimize" enabled by default then, if it does not work at all for the TopRouter? And how do we disable optimize for the TopRouter? Unlike the classical router, there are no "Active" CheckBoxes or "Del" Buttons.

Oh, I just answered my own own question: Take one of the classical variants and disable optimization by unchecking "Active" on all 4 tabs. Then save this configuration to a file, go to the TopRouter variant and load the just saved  file. Wow, that was easy...  :(

Could we get the V6 router back in V8, please?
 

Offline ReneK

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Re: TopRouter bug?
« Reply #10 on: September 03, 2016, 06:48:52 PM »
Jorge, I opened the "singlesided" project now and duplicated the setup from your video (preferred diections, effort, and so on). Then, after ticking continue, I went straight to the TopRouter variant and saved it into a file (without making modifications in the UI). In my text editor, I disabled optimization by setting all 4 corresponding "Active" to 0. After reloading the modified file, the jobs got started.

Now evaluate the TopRouter's result. It ends up with 188 DRC errors (clearance, dimension, overlap, restrict). What a mess! Disabling optimization is clearly not the solution, and this is why you removed that option from the UI. Result attached.
 

Offline jgarc063

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Re: TopRouter bug?
« Reply #11 on: September 07, 2016, 01:55:06 AM »
Hi Renek,

You are correct. I'm going to talk to the autorouter developer and I'll get back to you guys with whatever info he tells me.

Let me know if there's anything else I can do for you.

Best Regards,
Jorge Garcia
 

Offline ReneK

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Re: TopRouter bug?
« Reply #12 on: October 06, 2016, 06:45:13 PM »
Hi Jorge,

did you have a chance to talk to the autorouter guru yet?

Rene
 


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