New to Eagle - Routing help

[Hengy]

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:

An externally hosted image should be here but it was not working when we last tested it.

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.

An externally hosted image should be here but it was not working when we last tested it.

Thanks,

Hengy

 

[nigelwright7557]

Easiest way is to disconnect the wires and reconnect them how you want them.

I lay out the components as I want them before routing any tracks.

 

[Nisbeth]

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.

 

[nigelwright7557]

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.

 

[Hengy]

Thanks for the responses. I assumed that the traces were somehow routed in relation to the schematic. I'll try the ratsnest button!

Thanks, Hengy

 

[nigelwright7557]

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]

I pretty much figured it out! I just needed to sit down and experiment.

This is the result.

An externally hosted image should be here but it was not working when we last tested it.

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

 

[marce]

Look up acid traps, basicly the acute angles where some trace3s come out of other traces (above C6).

 

[dchisholm]

Look up acid traps, basicly the acute angles where some trace3s come out of other traces (above C6).

The DRC on some PWB layout programs will find and flag these. Don't know if Eagle has that feature or not . . . but in general I think it's worth the time and effort to learn how to set up and use automated DRC.

Dale

 

[marce]

It is also worth getting to see them visually which will come with experience especially on simple designs such as this one, and where they stick out visually like a sore thumb. But if you dont know what you are looking for you wont see them so...
Does Angle Matter? | Hot Wires

http://www.dnu.no/arkiv1/multek_20030925_DFM.pdf

 

[Hengy]

Thanks for your posts.

I didn't know, and wouldn't even have guessed that there was a problem with acute angles.

I will fix this.

Thanks, Hengy