ECE101 – Basic Electrical and Computer Engineering

Merging – A Complicated Process

One of the biggest frustrations I faced when I started using EAGLE was the apparent inability to merge a board in EAGLE.  I say merge, because making a copy of a current project is simple: just go to File, click Save As…, and you’ll create a new copy of your board and/or schematic.   If you want to combine two boards and/or two schematics, it seems like you can’t.  You can only have one schematic/board pair open at a time and you can’t copy between instances of EAGLE.  After some digging and experimenting though, I can tell you it is possible and I’ll tell you how to do it.

Combining Two Boards

Let’s imagine you’re working on a project with a friend or classmate and want to divide the work.  You do your part of the board, your partner does the other part, and at the end you plan on doing a copy-paste and send the board off to a boardhouse.  But when it comes time to copy and paste, you realize that it doesn’t work out.  For whatever reason, EAGLE has a less obvious approach to solving this problem.  Here’s how you do it:

1. Open one of the board files that you want to copy.

2. Using the Group tool, select the entire board.

3. Select the Cut tool, right click on your board and select Cut: Group.  (Note: Newer versions of EAGLE support copying as well.  However, if the schematic is open you will see errors about backannotation.)

4. Close your board (and schematic if it’s open) and create a new board (File -> New -> Board)

5. Click the Paste toolbar button and your copied board should appear.  Place it on the new board.

6. Save and close the new board.

7. Repeat the process, copying as many additional boards as you’d like into your new board file.

8. To add additional traces, use the Wire tool.  Since there are no signals associated with these traces, you’ll have to double-click when you want to end the trace.

Combining Two Boards with Schematics

Now let’s say you want to combine the two boards and define connections on the schematic so you can check for errors and have a complete schematic for your project for future reference.  To do this, you copy the board (as described above) and then the schematic (using the same method as for the board).  You’ll see errors about inconsistencies, but once you have copied the last schematic, these errors should go away.  In order to keep component names consistent, you need to copy the schematics in the same order that you copied the boards.