tag:blogger.com,1999:blog-38908275.post3511220651552493980..comments2020-10-30T06:55:59.671-07:00Comments on More noise than signal: Eagle Cad autorouter on fine pitch SMTSiliconFarmerhttp://www.blogger.com/profile/11434681826272098792noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-38908275.post-6696964809127083672011-02-05T20:32:47.210-08:002011-02-05T20:32:47.210-08:00Thanks for these posts about the Eagle autorouter....Thanks for these posts about the Eagle autorouter. I'm teaching myself how to use Eagle, and I find your posts very informative.<br /><br />I'm actually a programmer, though I do electronics as a hobby and recently started a job that combines both. From my point of view as someone coming over from the software side, I view the choice to autoroute or hand route as being analogous to the choice of whether to write a program by hand in assembly, or let a compiler do it.<br /><br />I can write assembly by hand, and I can do a better job than a compiler can, but it isn't the best investment of my time. In order to be productive as a programmer, I have to find ways to get the computer to do ever more of my work for me.<br /><br />So when I set down to learn Eagle I tried the autorouter and said, wow, this thing does some really goofy stuff that I don't like. Now I have a choice - I can either learn to hand-route, or I can fiddle with the autorouter until I figure out what makes it tick. If I hand-route I can make one board come out well, but if I learn the autorouter I can make all my boards faster.<br /><br />One thing I learned from this, while laying out a compact surface mount board, is that the autorouter actually does better the tighter you pack the components in. I guess it has less room to do something goofy.<br /><br />Thanks for sharing the tip about brining nets out partially & letting the autorouter complete them. I like to say "rip up all" and re-autoroute the whole board every time I move a component (I'm serious about making the computer do more of the work - and I have a fast CPU!) If only there were a way to mark "my stuff" different from "it's stuff" so that I won't lose my own routing. Perhaps put the hand-routing into custom device footprints? I did a similar custom-device trick to ensure the connectors for a board that mates to another board line up right: rather than laying out the headers that connect the boards by hand, I made a giant "device," the size of an entire board, that contains the mating headers. That way I don't have to worry about accidently moving a board mating header out of alignment. With my experience with software architecture, I am always looking for ways to abstract the parts that change from the parts that don't.Dennishttps://www.blogger.com/profile/03601234553344631838noreply@blogger.com