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Topic: Eagle Questions (Read 1 time) previous topic - next topic

aballen

I hope it is ok to post a few eagle questions here.  I'm making my own arduino based variant, all smt, and I have a few questions.

1) I've looked at a lot of schematics and noticed that all the components are not directly connected.  For example an icsp connector will just have labeled wires coming out, and then wires with matching labels are connected to the atmega168.  How do I do this?  I think the editor somehow knows that the wires are connected, dude to the lables, similar to GND, and VCC, I just dont know how, and I would make my schematics so much cleaner.

2) Are there any tricks to making a good dual sided board?  I have a tiny board created, all smt, but the autorouter seems to make a mess of the routings, if it does complete the board there at a lot of vias.. unlike the boards I've been looking at(arduino, boardunio, rbbb, dorkboard, funnell i/o etc)  I don't think I can manually wire a single side board that well, so double sided is way beyond my ability.  Is the trick component placement, can I let the autorouter run preferred componenets first, is there  a required amount of space between components for the auto router to work well?

Thanks in advance for your responses, I'm new to this, but I am learning a lot thanks to everyone input/feedback.

halley

#1
Jan 02, 2009, 01:34 am Last Edit: Jan 02, 2009, 01:34 am by halley Reason: 1
Each green wire in Eagle is a member of one "net" and each net has a name.  You draw parts how you want to see them, and attach green wires from each pin in each part.  Then you can merge or join one net with another, so even if they don't visibly connect, they are part of the same net.  Then when you wire the board with traces, any combination of real trace connections that satisfies all pins of a net will work.

aballen

Ok I plyed with changing the net name for wires and it seems to work, now back to my second question.  Are there any rules of thumb for laying out or spacing components on a board so the autorouter does a nice job?

westfw

No rules of thumb that I know of.  For small boards, it is fast enough to start with components far apart in random orientation, route, move things around and try again, repeat.

The Eagle autorouter is not very highly respected...

melka

I don't have a lot of experience with eagle & electronics CAD software in general, but I'd say that what worked best for me was to route some stuff myself (like a led matrix, pretty simple to do) and then hit the autoroute button. Sometimes eagle would do a mess with the simplest routes > lot of useless vias.
Oh, and don't forget to save your board before autorouting, I never found the "clear routing" button, so I have to delete all the connections by hand before another run. Maybe i'm just dumb, though ^^

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