Eagle PCB Design Help

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Hello,
I am attempting to create a PCB breakout board for the Atmega1280 in the TQFP100 package. I am new to Eagle PCB editor and have attempted to use some of the online documentation to modify the autorouter settings but still no luck.

The Atmega1280 Spec Sheet:
http://atmel.com/dyn/resources/p...

I would greatly appreciate any help in understanding the routing settings to get this atmel chip to route.!

Thank you.

-Jose

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The autorouter outputs pure, distilled and refined stacks of useless boards. I'd do it manually if I were you. Don't be lazy with yer boards!

There are pointy haired bald people.
Time flies when you have a bad prescaler selected.

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Or experiment a bit with the autorouters settings and fix the rest manually.

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Quote:
The autorouter outputs pure, distilled and refined stacks of useless boards. I'd do it manually if I were you. Don't be lazy with yer boards!

With all due respect to daqq, I use the autorouter in Eagle all the time with wonderful results. Manual routing drives me insane.

Try this:
1. In the DRC, sizes tab, set your minimum width to 10 mils.
2. Start the autorouter and set the grid for 10 mils.

How does this work for you?

If you still have problems, I would be willing to help with the routing if you send me the brd file.

Regards,
Paul

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I always use manual route. But, then my boards have a lot of RF and switcher on them and I am picky about getting a board that works.

You really DO need to set up the DRC. That controls line spacing and all sorts of other things that the autorouter needs. Also, take a good look at the Eagle Tutorial. It tells you a LOT about using the autorouter.

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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ka7ehk wrote:
Also, take a good look at the Eagle Tutorial. It tells you a LOT about using the autorouter.

Which tutorial are you referring to? Where is it located?

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And turn that IC straight. It may look cute but A: It will drive your autorouter nuts and B: Having it straight will actually create better routs in this occasion.

Go electric!
Happy electric car owner / builder

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Oh and get that crystal a whole lot closer to the IC!

Go electric!
Happy electric car owner / builder

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Tutorial is in the downloads section of www.cadsoft.de.

Go to "Documentation", then well down the page, there is a tutorial zip file.

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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> And turn that IC straight. It may look cute but A: It will drive
> your autorouter nuts

Curious, why?

I tried that layout on my autorouter (which is not an Eagle one), and
after fiddling a bit with the parameters (particularly the trace
width), it produced a usable result within about 10 minutes. Of
course, autorouter results are often not as esthetically pleasing as a
5-hour manual routing job, but that's another story.

(I didn't try the straight IC though, for a comparison.)

Jörg Wunsch

Please don't send me PMs, use email if you want to approach me personally.

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Yea I would like to know why the 45 degree angle would mess up the auto router. You would think it would make its life easier.

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I'm assuming that the Eagle *free* autorouter is not a super-sophisticated router. It will probably be thinking in orthagonal space. So what will happen is you get a huge number of little steps near the IC pins and or the connector pins. Even if it isn't thinking orthagonally, spacially it makes more sense to route a vertical row of pins to a vertical row of pins. Now, if you allow for "any angle" on your routes then the diagonal placement would work nicely. However, in the long run this is a bad habit to get into. Perhaps I'm being a bit pedantic but I got the feeling that the OP was looking for learning.

My statements are opinions and not facts! Shit everytime I post a fricken opinon on this site I get pounded. I think I'm going away from this place for awhile. If you don't like my opinon then don't read it. I don't care. I'm a successful engineer that might...just f'ing might have some experience.

Go electric!
Happy electric car owner / builder

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Eagle does angle runs quite well if you enable them. Default IS right-angle corners.

So, without trying it, I suspect that sgomes is right (unless you take care to enable angle rungs).

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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Never, ever auto route. If you're very lucky and spend a very large amount of time learning all the settings and tweaking alot, you may get an almost usable result with it.

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Well, the point of having to spend 5 hours (or more) manualy routing is valid. sometime you want a quick & dirty routing for a test circuit, and don't want to do the 'proper' manual routing.
In that case I'd love the autorouter to a a better job too, it has a hard time 'hitting' the pads, and it's fairly common to have to re-scan the board and fix it... But it still takes less than 5 hours :D

And whats wrong with 45 degrees ICs ? I love it :D

Author of simavr - Follow me on twitter : @buserror

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sgomes wrote:
And turn that IC straight. It may look cute but A: It will drive your auto router nuts and B: Having it straight will actually create better routs in this occasion.

OK! I'm not being critical here but, if you look at the PCB that buserror just posted...

You'll see that the IC package on a 45 degree angle actually provides a lot more room. If the IC package was square to the header pins, the traces along the IC pins parallel to the header pins would actually be a lot more congested.

By placing the IC package at 45 degrees relative to the header pins, there is space to spare.

The fact is, there is a real possibility that the PCB that buserror posted might very well have been able to have been laid out as a single sided PCB. Whereas, if the IC package were squared up with the header pins, a double sided PCB would more then likely be a necessity and, the traces would have been much more congested and, a lot more vias would have been required.

In my twenty years of working with the DOS based HiWire II PCB layout software, there were many, many times I wished I could have had the ability to position the IC packages at 45 degree angle, simplifying the single sided PCB layout.

Oh! Did I mention that, while I have laid out my share of double sided PCB (and they are easier) I have a personal standard and goal to make every PCB single sided. I've done a couple hundred single sided PCB over the years and 90% were single sided.

You can avoid reality, for a while.  But you can't avoid the consequences of reality! - C.W. Livingston

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sgomes wrote:

My statements are opinions and not facts! Shit everytime I post a fricken opinon on this site I get pounded. I think I'm going away from this place for awhile. If you don't like my opinon then don't read it. I don't care. I'm a successful engineer that might...just f'ing might have some experience.

Who pounded you? Did I? Sorry if my two sentence comment offended you, I was just trying to get more information on why 45 degree angles are bad. Didn't mean to offend anyone.

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There was a thread recently, like "Do you autoroute?". 45 angled ICs provide a LOT more space, in the case you have a board like

PINS         pins
 ..           ..
 ..    IC     ..
 ..           ..

Even the most 90deg. people must see this, when they look at BusErrors board.
However, if the board was like

Pins everywhere around. 
............
..   IC   ..
............

Then placing it in a 90deg. angle would serve better. Most likely. IMHO :-)

There are pointy haired bald people.
Time flies when you have a bad prescaler selected.