New to Eagle - Routing help

Hengy

Member
2009-10-12 10:16 pm
Canada
Hey guys,

I am doing my first PCB design in Eagle. I made most of the parts custom, and then followed the tutorials on Sparkfun.com.

I am new to Eagle, so searching for a solution to my problem has been hard, as I do not know the names of the tools, etc.

My problem is, that when I go to the board view, Eagle connects the wires.. wrong. Here is a pic of it, with [one of] the problem areas highlighted:

[IMGDEAD]http://matthengeveld.com/np100v12/eagle_board_wrong_fix.png[/IMGDEAD]

The wires connecting the starred points, I want to connect from U$1 to U$2. It probably makes more sense if I explain that U$3, U$2 and U$1 are filter caps, and the unlabeled rectangle beside it is a toroidal power inductor. I want all grounds and power to come from the last capacitor.

Here is my schematic. I used the Net tool.

[IMGDEAD]http://matthengeveld.com/np100v12/eagle_schem.png[/IMGDEAD]

Thanks,

Hengy
 
The ratsnest wires are always the shortest rout. If you move the components around and click the "ratsnets" button (lloks like a cross) they will change. You can also route traces as you want them and the connections will be made the way you like.

/U.

The trouble with the shortest route is it doesn't always match up with a star ground route. Star ground can be much longer.

Nigel Wright Designer of PCBCAD50.
 
I cant speak for Eagle but my software connects the pcb the same as the schematic to start with. Although this can be complicated by tagged tracks in which case they connect as they are organised in memory (or time of connection).

I then have an "optimise net" function which reduces the ratsnest to the minimum length.

Another good function (which I don't think Eagle has) is a "swap autoplace" function which exchanges positions of same component types until it finds minimum net length.
 

Hengy

Member
2009-10-12 10:16 pm
Canada
I pretty much figured it out! I just needed to sit down and experiment.

This is the result.
[IMGDEAD]http://matthengeveld.com/np100v12/np100v12_power%20supply_board.png[/IMGDEAD]
and the files are linked here

Can someone be kind enough and take a look for mistakes, things I've forgotten, or anything? It would be a great help, and a lot easier than finding out after I get it in the mail!

Thanks, Hengy