SparkFun Forums 

Where electronics enthusiasts find answers.

Questions relating to designing PCBs
User avatar
By bigglez
#34529
jandirks wrote:I have made a schematic in Eagle and when I want to 'Change to board', I get an error message saying: Unknown object type.
Greetings jandirks,

Try to open another EAGLE schematic (preferably from another author) and then switch to board. This will isolate the problem to EAGLE or the particular schematic file that you've created.

Let us know what you discover. Comments Welcome!
By jandirks
#34530
Thanks Peter,

I could open another board, I tried the hexapod sample. That board could be opened fine from within the schematic drawing.

Then I tried to open my own schematic again (different computer this time) and got the same problem when changing to board. Another message I sometimes get (and sometimes not get) with this design is 'cannot perform forward/backward annotation'). I tried to reproduce this error now, but it appeared a couple of times this afternoon.

Anyway, still have the same problem. More suggestions welcome!
User avatar
By bigglez
#34531
jandirks wrote:I could open another board, I tried the hexapod sample. That board could be opened fine from within the schematic drawing.

Then I tried to open my own schematic again (different computer this time) and got the same problem when changing to board. Another message I sometimes get (and sometimes not get) with this design is 'cannot perform forward/backward annotation'). I tried to reproduce this error now, but it appeared a couple of times this afternoon.
jandirks,

Good! Let's address the second issue first, the error
regarding back annotation will appear if the board
and the schematic get out of sync. This can happen
if you only open the board or the schematic editor
and close it again. Not sure if this is a flaw in the
otherwise excellent software, but a rule to follow is
to open both the schematic and the board anytime
you do a project (even if you only open a completed
project to print or review on the screen).

I assume that you have a legal copy of the program?
Also, that you have not opened anyone else's EGLE
files on your system? There is an issue for anyone
that has tried to break the security.

Next, go back to your schematic and run the ERC.
Make sure there are no error messages, and that any
warnings given are acceptible to you (for example the
component may have a Vdd pin that you've connected
to a 5V net - which is legal but generates a warning).

Now close EAGLE and use the OS file browser to view
the folder (directory) for this project. Look for any files
with *.brd or *.b#(a digit), and delete them. Go back
to EAGLE and open your schematic again, try to create
a board from it.

Let us know if this works, Comments Welcome!
By jandirks
#34549
Hi Peter,

Thanks for all your suggestions!

Regarding the annotation error. I don't have that error anymore, it seems. This one is solved.

I have the free version. No illegal key, crack or whatever has been used. It's just a download from cadsoft.de and I installed it . I am doing this as a hobby and hope to learn a few things with it. Whenever I get something that I am going to sell, I will buy it.
Also, never opened anyone else's schematics, only the examples that came with it and my own designs.

I tried your suggestion to remove the .brd and b# files. This wasn't a solution too. Still getting the same error.

Maybe I should start over with this design?
By Philba
#34553
before you start over, make a copy and start deleting things from the schematic. use a binary approach to quickly narrow it down (delete half the components, see if the error is still there, narrow it down, repeat).

then go back to the original and delete the offending item. Better than starting over.

I too have seen the "phase" error that happens if you close the board and make changes to the schematic. Just not a good idea at all. I recall that there is a "good" reason for this problem but eagle simply shouldn't let you shoot yourself in the foot.

One other possibility is that the library that the component is in got changed.
By jandirks
#34613
Great suggestion to not start all over again. I found the culprit within 5 minutes. It turned out that after removing crystal Q1, the problem was gone.

I replaced with a different one and now it works fine.

Thanks for your suggestions and help!

JD