Duemilanove Eagle file, what design rule file (*dru) is being used?

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1

I'm finding when I do a design rule check on the Duemilanove PCB design gotten from (http://www.arduino.cc/en/Main/ArduinoBoardDuemilanove) using a recently downloaded freeware version EAGLE, I get 410 errors. I'm guessing this is because I'm not using the right dru file (though it could be a version problem or something else). Anyone know what I'm doing wrong? Must I use an older version of EAGLE? Is there a .dru file I should be using? Something else?

Thanks in advance

2

Part of the problem is that the duemilanove board file has a lot of layers turned on by default.
Turn off the soldermask layers, and you'll get a more reasonable count (about 30.) (EAGLE only displays DRC issues in the soldermask layers if they are actually turned on.) This probably mean that any DRC checking done on the reference design was done without considering the soldermask, or adjusting the soldermask rules to match the other aspects of the design.)

(Unless you specifically load a new DRC file (in your inits, or similar), the DRC parameters used for a board are carried with the design files themselves, so errors should NOT be dependent on your local environment.)

3

Thanks westfw,
That's a fairly annoying thing in an open-source bit of hardware. I'd have thought that they'd either approve the errors, fixed them or modified the design rules. It makes modifying this more than a bit tricky. Ah well. The Uno has the same kind of problems.

I can see some of the drc issues are frankly not important. For example the top metal layer is sometimes used as "art" and so width doesn't matter too much. But other rule violations appear problematic (metal layer too close to a via for example). Bah.

Thanks again for the help.