Using Eagle for Schematic Capture ONLY

On 16/03/14 03:05, ezrcer wrote:

I want to use the Schematic capture tool but not the layout tool.  I

tried to make some devices that had symbols but no package foot print.

I noticed that I cannot place those on a schematic page.  Why?

 

The layout tool that I will use will have the package footprints.  I

only need to pass the package part number in the netlist.  What is the

right way to use Eagle ONLY as schematic capture tool?

 

Surely if you expect Eagle to export the package names, and the correct

pin allocations for the nets, then you need to define (somewhere) both

the packages used by a component and the pin-out mapping from the

symbol. I would have thought that the library was the most obvious place

to do this and the standard mechanism the most convenient one.

Also, there may be cases that I may want to do the schematic before

making all the footprints and attaching to device in the library.

 

It's certainly possible to do this with components where not all the

available packages are defined, add the one you want later, and use

"CHANGE PACKAGE" to correct it. So if the library has an IC in a DIL

package you can use that, then add the TSSOP to the library later and

adjust your design before layout out the board.

What I've done in the past for schematic only (particularly when drawing

wiring looms) is to define parts with completely dummy packages. There

may be a better way.

Thanks very much!

I guess I can just assign some pins in a dummy package for this type of application.  The point is NOT to actually spend time drawing the package PAD geometries

Regards,

Yes, that's right. The package must have the same number of pins/pads as the symbol, plus the power pins if you are going to declare power connections that way. One little thing, unless I've missed it, in the editor for a new device there doesn't seem to be a menu item 'make package' and you have to type the command 'package'.

Slighly more obscure, if your symbol has no pins you don't need a package, in theory. However, there was a post a while back that to the effect that it's best for reliability to make one. Just type 'package' and save the empty window (you could draw a circle or something so it doesn't seem odd). I use that method to draw a stripboard pattern and strip breaks as a guide to laying out stripboard using the schematic editor.

Yes, it can be frustrating how tightly clings to its "every symbol must have a package!" rule.  When I'm laying out a schematic, I don't want to worry about 1206 vs 0603, SOIC vs QFN, etc.  Let me put the symbol now, and worry about the package later!

You can just drop the right number of pads into a package and have all your symbols with the same number of pins share it.  Leave the default pad naming and everything.  I'd name them NULLPKG14, NULLPKG24, etc.  Should take all of 20 seconds.

Christopher Lee wrote:

Yes, that's right. The package must have the same number of pins/pads as

the symbol, plus the power pins if you are going to declare power

connections that way. One little thing, unless I've missed it, in the

editor for a new device there doesn't seem to be a menu item 'make

package' and you have to type the command 'package'.

 

Slighly more obscure, if your symbol has no pins you don't need a

package, in theory. However, there was a post a while back that to the

effect that it's best for reliability to make one. Just type 'package'

and save the empty window (you could draw a circle or something so it

doesn't seem odd). I use that method to draw a stripboard pattern and

strip breaks as a guide to laying out stripboard using the schematic

editor.

read about "Devices without packages" in the online help of the

package command.

--

Lorenz

On 3/20/2014 5:30 PM, Scott Bronson wrote:

Hi Scott,

EAGLE ships with a ULP for making dummy packages for this purpose, that

way in just a couple of clicks you're done with your part. Its only in

german that's why a lot of guys miss it.

e-packages-aus-devices.

Even though the help is in german its pretty self-explanatory.

Best Regards,

Jorge Garcia