Have a question about CadSoft EAGLE?  Ask our Expert, Richard! (Archive)

Hi Gary,

as you just did... 

Richard

How do I ask Richard questions?

Hello again,

I am not sure what you exactly want to do....

As far as I understand you want to write an ULP that places vias in your layout, correct?

So you have to write an ULP that executes commands in the EAGLE layout editor. It is useful to let the ULP create a script (which contains a number of EAGLE commands executed subsequently) for your purose. Look into one of the ULPs in order to get out how this works, for example into change-via-by-stack.ulp:

Here a short part of it where we create a script file that will be executed:

board(B) {
    script = filesetext(B.name, ".scr");
    output(script, "wtD") {  // temporary file
      set_layer();
      B.signals(S) {
        S.vias(V) {
          if (V.start == via_start && V.end == via_end) {
            if (stack) printf("CHANGE VIA %s (%.4f %.4f);\n", new_stack, u2mm(V.x), u2mm(V.y) );
            else {
              if (v_shape) printf("CHANGE SHAPE %s (%.4f %.4f);\n", v_shape, u2mm(V.x), u2mm(V.y) );
              if (strupr(argv[3]) != "NO") {
                if (v_drill) printf("CHANGE DRIL %.4f (%.4f %.4f);\n", v_drill, u2mm(V.x), u2mm(V.y) );
                else         printf("CHANGE DRIL (%.4f %.4f);\n", u2mm(V.x), u2mm(V.y) );
                if (v_diam)  printf("CHANGE DIAM %.4f (%.4f %.4f);\n", v_diam, u2mm(V.x), u2mm(V.y) );
                else         printf("CHANGE DIAM (%.4f %.4f);\n", u2mm(V.x), u2mm(V.y) );
              }
            }
          }
        }
      }
      printf("GRID LAST;\n");
      printf("DISPLAY NONE ");
      B.layers(L) if (L.visible) printf(" %d", L.number);
      printf(";\n");
    }
  }

dlgDialog("test") {
  string text;
  int t = fileread(text, script);
  dlgTextEdit(text);
  dlgHBoxLayout {
    dlgPushButton("OK") dlgAccept();
    dlgPushButton("esc") { dlgReject(); exit(-1); }
    dlgStretch(1);
  }

........................

........................

........................

  exit("SCRIPT '" + script + "'\n");

The output() statement creates the file, printf() writes the commands into the file. exit() executes the script file.

Hopehis helps......

Regards,

Richard

Dear Richard,

Again, sorry for my bad english . I have a task to draw my schools symbol from vias, using ulp. I can calculate the coordinates for the vias in my ulp, but I can't draw any. In my another discussion you answered me, that is have to use a script. My question now is how can I autorun and than delete the script after the ulp was executed?

Thanks for your help.

Hi K Sz,

I do not fully understand what you would like to do, but if you want to place a pad... This can be only done in the library in the package editor. In the layout editor you have to use a VIA. Or do you want to place a component in the layout?

Could you please give me some more information?

Regards,

Richard

Richard,
I'm using Eagle 5.11 and i have a task to write an ulp, that draws a logo from pads. My question is: why i can't draw a single pad with ulp? This is my only obstacle and i cannot finish my ulp. I would like to know, how to draw pad with ulp. I looked in some files, but unfortunately it didn't help. Sorry for my bad english.
Thanks for your help.

Hi Joe,

you can use two pads as well. Best would be then to use two pins and connect them both with the signal....

Currently there is no better solution. We have to wait for EAGLE version 6. There we will have the possibility to connect one pin to several pads and it will be possible to draw arbitrary pad shapes with a POLYGON or WIREs. There won't be DRC errors and polygons in the layout will be connected or isolated properly.

Best regards,

Richard

BTW: You know that "Adler" is the German word for "eagle"?  SCNR... 

Hi Robert,

you have to draw restricted areas. As far as I know there are some ULPs that could help here. It is possible to route the nets by classes, there is a ULP that draws restricted areas on all pads on top layer. please look at http://www.cadsoft.de/downloads/user-language-programs/ and use the search function. "auto" should give some results.

Regards,

Richard

Richard,

Thanks for the quick reply.

I find that when I make the library part, if I just add another square pad to cover one round end of the test point pad, I wind up with the shape I need wiithout having to draw any polygons.

The stop layer is made automatically and shows up on the PCB when I enable the layer to see it.

The only problem I still have is that when I connect the PAD to ground and pour a ground plane, the section of the PAD that is made by the square does not connect to ground.  The other part of the pad (the part with the two rounded ends) connects just fine.

I was thinking of making another PAD that would have a separate connection for both pads and I would just connect both to ground on the schematic.

I hope this makes sense.  Anyway, thanks for your help.

Richard,

Thanks for all the helps so far, you've been great. I have problem with Eagle and I'm stumped to find an answer. Before I send our boards out I prototype them here. Because we can't do certain operations like running the top layer to thru hole capacitors we need to stop the auto router from running the top layer to those locations. We have been using the restrict layer to keep the top tracks from those locations but this is tedious on larger boards. Is there a simple way we can limit track layers to certain packages? Maybe when 6 comes out if not now?

Thanks,

Robert