Unrouted Airwires

Am 21.01.2013 23:37, schrieb Bob Moreno:

It seems to me the DRC should have an unrouted airwire alarm/message, whatever, something.

Some thoughts about that:

  1. As pointed out, unrouted wires might VERY well be a design

     error, so the DRC should BE ABLE to find (and show) them

     properly.

  2. As pointed out, the numbers of errors at the beginning of

     the route process would be enormous, so

      - the user MUST be able to turn this option on or off,

      - and the default for newly created borads should be OFF.

  3. Even with

       DISPLAY None Unrouted;

       GRID Off;

     it is sometimes hard to see unrouted wires, because they

     might be of 2um length, because some mistake happened

     sometime during the routing (prior to the better snapping

     feature of version 5, this happened HUNDREDS of times with

     SMDs, now it STILL happens rarely).

  4. Fiddling around with catch factors etc. is - pardon me -

     hacker rubbish: Nobody but experts knosw about this, and you

     definitely don't want to use a catch factor of 100% during

     your 'normal' work. Therefore, you would need to change

     the catch factor a thousand times during design. No,

     please. There should be a PROPER way to do things that

     EVERYBODY can use. The DRC is where everybody searches

     this feature, and it should go there.

  5. Even IF one uses 100% catch factor, you cannot immediately

     see WHERE you route WHAT: Suddenly, you might have

     terribly long copper wires all across the board, wonder

     where the heck they come from, manually pan and zoom, guess,

     etc. The user should know what will happen BEFORE the actual

     routing takes place.

  6. Even worse, if there is MORE than one airwire left, and

     some of them should even STAY airwires (e.g., because these

     are long wire jumpers, or connections between two boards),

     one might not even be able to ROUTE the remaining airwires,

     because one doesn't know beforehand where they ARE (and the

     large catch factor always catches those that should STAY

     unrouted).

Since several things are missing in the DRC, I had to write some

additional 'check.ulp' some years ago, which introduces the search for

unrouted wires as one option: It shoes all of them in a list box, and

double-clicking on a line zooms into the board and shows the airwire.

Unfortunately, there is no possibility to approve such errors, so if

uncorrected, they will ALWAYS show up again. Having this in the DRC

would be MUCH nicer.

And yes: THIS probably is the MAIN problem with putting that nice

functionality into the DRC. How can one properly approve of such errors?

Airwires are calculated automatically and might show up everywhere, so

their position is not absolutely fixed, and the DRC might 'forget'

approved errors later.

Andreas Weidner

Andreas Weidner wrote on Wed, 23 January 2013 17:16

1. As pointed out, unrouted wires might VERY well be a design

     error, so the DRC should BE ABLE to find (and show) them

     properly.

No, it shouldn't.  That is inappropriate use of the DRC check.  That would

make most other uses of it really really tedious.  You could possibly run

the DRC check many times during routing.  It is useful catching what it is

intended for, which are design rule errors.  Of course there are going to

be a lot of unrouted nets as you are progressing thru routing.  You don't

want those in your face all the time.

As you are doing routing, of course you are looking at the number of

unrouted nets left.  That's how you know you're done.  What you really want

is a check after you think you are done routing.  If simply looking at the

number of unrouted nets isn't good enough for you, then you could run a ULP

that checks for that.  Of course, if you remember to run the ULP you could

just as well remember to look at the number of airwires.

A better solution would be to have the CAM processor check.  That's the

only time Eagle actually knows you think you are done routing.  That's the

only time I'd tolerate something popping up warning me that there are still

unrouted airwires, if by some bizarre coincidence or complete brain

collapse I thought I was done routing despite it showning more than zero

unrouted nets.

DO NOT make this a DRC check.  That would make things difficult 99% of the

time in favor of rare case.

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Am 23.01.2013 23:39, schrieb Olin Lathrop:

Of course there are going to

be a lot of unrouted nets as you are progressing thru routing.  You don't

want those in your face all the time.

You might have noticed the following sentences I wrote in which I stated

EXACTLY this, and also proposed that this DRC check CAN be done, but is

switched off by default, so the user can enable it when the time comes

to finish the board.

Andreas Weidner

I think it would be nice if the Unrouted Airwires flashed.

Best,

Bruno2000

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I think it would be nice if the Unrouted Airwires flashed.

Best,

Bruno2000

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