Mail Archives: geda-user/2014/07/23/13:41:21
On 07/23/2014 10:04 AM, gedau AT igor2 DOT repo DOT hu wrote:
>
>
> On Wed, 23 Jul 2014, Dave Curtis wrote:
>
>> On 07/22/2014 09:11 PM, gedau AT igor2 DOT repo DOT hu wrote:
>>>
>>>
>>> On Tue, 22 Jul 2014, Dave Curtis wrote:
>>>
>>>> Has anyone seen a description of the Eagle .dru (design rule) file?
>>>>
>>>> I notice that a lot of fab houses publish Eagle .dru files for their
>>>> process, and it might be a quick/easy project to create a .dru to PCB
>>>> design rule translator for most of the common/meaningful rules.
>>>>
>>>> It's a plain text file with a bunch of names and values, so it
>>>> wouldn't exactly be rocket science to reverse engineer, but I thought
>>>> someone might have run across a document on it. I haven't been able
>>>> to snag anything with Google.
>>>
>>> If it's that simple, we could write a script that creates/replaces the
>>> DRC part of a pcb save. Could you attach some examples?
>>>
>>
>> oshpark publishes their rules here:
>> https://oshpark.com/LaenPCBOrder.dru
>>
>> if you google for 'dru' you get more hits of fab house dru files than
>> about anything else.
>>
>> I don't really think it makes sense to modify the drc part of PCB's
>> save, as the two sets of design rule specs probably don't line up
>> really well. But maybe a "load rules from dru file" menu selection
>> would be good -- it could read a .dru file and pick out the pieces
>> that make sense, then just go forward with PCB in the normal way.
>
> There are two different things here:
>
> 1. how much the pcb drc and the information in a dru can be matched up;
> dru seems to be much more detailed. Extending PCB (feature-wise) to
> support more of these details probably would be a large effort. Finding
> out how to convert the information from the dru to PCB drc setup in a
> way that a drc-accepted PCB design won't voilate the dru seems to be
> easier. Of course because of the less detailed drc in PCB this also
> means a drc-accepted design won't exploit all possible limits.
Yes. Just guessing from the names, the .dru file I linked looks like
there are track-to-via, via-to-via, track-to-track, etc, minimum spacing
rules that could be all different. It seems to me that to convert to
PCB rules we would simply pick the max of all of those to be the minimum
clearance, for instance.
>
> 2. once we have such PCB drc settings derived from the dru, we need to
> apply them to a design. Your suggestion is that it should happen within
> PCB; my suggestion was to have a separate script. At the end the two
> solutions would produce roughly the same effect, only the UI would
> differ: the design you are working on in PCB is the same thing that the
> design saved in the file. There is only one set of drc there. If you
> make pcb directly manipulate the in-core representation of the drc
> settings, they will be saved in the PCB file on the next save. Which is
> the same thing as if you have a script that modifes the saved file and
> the next time you load it in PCB it already has the new drc rules. At
> the end the drc section of the design is changed to match the dru.
> Unless you meant a second set of drc rules existing only while PCB is
> running and never saved, or direct support for dru on top of drc... But
> these are both the hard way mentioned in point 1.
What I want is quite simple: translate the fab house rules into the
settings for the PCB rules dialog box. It can be automatic, it can be a
report. For my needs, I want the rules settings to be available in PCB
at design time. Either the dialog or updating the save works.
>
> The file format seems to be simple. If someone collects the rules how to
> convert these values to pcb drc values, I can easily write a script that
> manipulates pcb saves. By rules I expect things like "PCB's drc
> somesetting should be equal to min(dru.x, dru.y, dru.z)."
Yes. I agree. The script is quite easy -- the work is in understanding
the .dru file, which is why I was wondering if anyone had seen a spec
:-/ ... otherwise it will mean downloading a copy of Eagle and poking
at it to see what changes in the .dru file.
>
> My fab house doesn't have dru, so it's not a feature I really need, so I
> wouldn't invest my own time in figuring the matching nor would I try to
> implement a more integrated solution, but can volunteer to write a small
> script.
>
> Regards,
>
> Tibor
>
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