Eagle - Is it possible to make the un-routed GND airwires a different color?

[Pigyboy]

I always think it would be a lot easier using Eagle to layout boards if it were possible to make the un-routed airwires that are defined as GND a different color. If you use Eagle to any extent you will know what I am talking about. It can be confusing laying out a board with lots of parts with all the yellow airwires.

Is it were possible to differentiate the GND airwires from the others in anyway?

Thanks,
Chris

[edvard]

I don't think so.
I'm not at home right now, but I'm pretty sure there is a spot where you can set the color of the airwires, but it's a 'global' setting.
Actually, I think that'd be a great feature to color-code airwires by net name or some such.
It would make hand-routing a little less of a chore if you knew what was most likely to go where.
Red for power, blue for signal, green for ground, white for control, etc.

Anybody know how responsive CadSoft is to feature requests?

[Pigyboy]

Yeah - That would make it much easier. I bet it is on the paid for version...

[Pigyboy]

Ok this isn't perfect but it helps - Check it out..

Once you have laid at least one piece of the GND signal(you'll need this to find the GND signal again) click the info function and then click on the GND signal and it gives you all the details. There is a box called hide airwaves and if you check it it hides the GND signal thus giving you fewer annoying yellow lines running everywhere.

When you want to se them again click for info on the piece of GND that you can see and unclick the airwaves box to see them again.

I just figured this out and am not sure if it will make things easier but we'll see...

[Gurner]

to change the colour of airwires...

1. click on the 'display icon (the icon that has 3 coloured squares - under the i on the left of your screen)

2. Double click on 'Unrouted'

A new popup window appears ....click on the colour box .....select you other colour *there don't seem to be that many available!)

Edit: Apologies...just read your requirements again - hey ho (the above setting is glbal) ....must pay more attention!

[chi_boy]

Ok this isn't perfect but it helps - Check it out..

Once you have laid at least one piece of the GND signal(you'll need this to find the GND signal again) click the info function and then click on the GND signal and it gives you all the details. There is a box called hide airwaves and if you check it it hides the GND signal thus giving you fewer annoying yellow lines running everywhere.

When you want to se them again click for info on the piece of GND that you can see and unclick the airwaves box to see them again.

I just figured this out and am not sure if it will make things easier but we'll see...

This is the way I do it and I think it works fine.  It's make it much easier to focus on the parts and not be distracted by the GND airwires.  I follow the Gaussmarkov GND pour tutorial too, so everything falls into place nicely.  Just make sure to unhide the airwires when you think you are done just to make sure you don't have any orphans.

[Pigyboy]

I can second chi_boy's method now that I have tried turning the GND airwires off.  It makes it easier on the eyes. 

Thanks!

[R.G.]

There is an old concept in design automation from bad old days when wires were selected for routing by a scoring polynomial. This produced a numerical score per net for how crucial the net was to route; the highest-priority nets were routed first.

Close on the heels of that was the realization that some nets didn't need to be scored at all, because they should always be the last thing routed. Oddly, power supplies and ground turned out to be the best examples of this. Ground goes almost everywhere. Power is nearly as ubiquitous. No reason to score them. I routed power next to last and ground last in all layouts, then look at current distributions in the cleanup pass.

You've rediscovered this concept by intuition. Good work.

[Pigyboy]

Thanks RG. It makes sense when you put it into Spock logic 

[Pigyboy]

Hey RG,

If you see this can you explain what makes a net high priority? 

I am going to try different layout methods - Like placing the power rails first then working around that or finding the junctions with the most parts on it and build out from there. These seem like logical starting points....

I seem to find no method in working from input to output but sometimes I find it works better to work output to input.

Thanks,
Chris

[R.G.]

If you see this can you explain what makes a net high priority? 

I am going to try different layout methods - Like placing the power rails first then working around that or finding the junctions with the most parts on it and build out from there. These seem like logical starting points....

I seem to find no method in working from input to output but sometimes I find it works better to work output to input.

Neither one of those. The point of a lot of routing is to (1) NOT block later-routed traces and (2) keep things compact. So you route the shortest traces first, and route outwards from (a) first the things that can't move and (b) the things with the most pins.

I'd suggest a copy of my book on PCB layout, but Small Bear is out of them and I'm having trouble getting the publishers to deliver the next batch on time. But they should be there soon.

[Pigyboy]

Thanks RG

Would you PM me if it is possible to buy a digital copy of the book from you now?

Thanks,
Chris

[R.G.]

Would you PM me if it is possible to buy a digital copy of the book from you now?

Sorry, but no.

I do apologize, but the way the internet works is that if I sold digital copies, they would be copied to sharing networks semi-instantly and appear all over the web. I'm not saying that you personally would, but I made the policy long ago not to do that.

I'm having more printed; it's just taking longer than I thought. So they'll be in stock at Small Bear and the other dealers Small Bear supplies in the near future.

Again, sorry for the delay.

[Pigyboy]

Hey No Worries RG. 

It has forced me to think about what you have said already and it is helping in a bit of a complicated layout I am trying to do.  I buy lots of stuff from Steve so I will pick up a copy when they do come in.
I appreciate all the help so far.

cheers,
Chris

[robmdall]

Checking out the threads relating to Eagle and I found this one. A good solution to the OP (if I read it correctly) is to use the Ratsnest command. The command allows you to hide and unhide any signal you want. Hers a short excerpt from the Help file:

Hiding selected airwires
Sometimes it may be useful to hide the airwires of selected signals, for instance if these will later be connected through a polygon. Typically this could be supply signals, which have a lot of airwires that will never be routed explicitly and just obscure the other signals' airwires.
To hide airwires the RATSNEST command can be given the exclamation mark ('!'), followed by a list of signals, as in
RATSNEST ! GND VCC
which would hide the airwires of the signals GND and VCC.
To have the airwires displayed again just enter the RATSNEST command without the '!' character, and the list of signals:
RATSNEST GND VCC
This will activate the display of the airwires of the signals GND and VCC and also recalculates them. You can also recalculate the airwires (and polygons) of particular signals this way.
The signal names may contain wildcards, and the two variants may be combined, as in
RATSNEST D* ! ?GND VCC
which would recalculate and display the airwires of all signals with names beginning with 'D', and hide the airwires of all the various GND signals (like AGND, DGND etc.) and the VCC signal. Note that the command is processed from left to right, so in case there is a DGND signal the example would first process it for display, but then hide its airwires.
To make sure all airwires are displayed enter
RATSNEST *

[Pigyboy]

Thanks for the info Rob.  I also figured out you can pick the Info function and when you pick a trace a window opens with all the details and there is a box you can check called 'Hide Airwaves'.....