Hi, I’ve made some small progress up the Eagle learning curve.
Because I use Laserjet toner transfer, I try to keep the track width up and autoroute a single sided board to avoid track misregistration problems. Even with only 3 or 4 components this can be difficult, but I’ve learned some tricks like using DIP rather than PLCC so tracks can route between pins.
Now I have a problem with a small board which can route single sided EXCEPT for the signal GNDs. I poured a ground plane and called it GND. That linked most of the grounds leaving a couple of ‘isolated’ polygons. OK when I looked at the pour it was obvious what that mean’t - autorouted tracks around ground ‘islands’ with no connection.
So then I thought going double sided using the top side as a ground plane with a couple of vias would do the trick and registration using thermal toner transfer would be easier than having the top side full of tracks.
My top ground pour has the signal net name N$21. When I try to rename it to GND same as the bottom layer I get the Eagle error message Signal name ‘GND’ already exists! use the NAME command to combine signals.
I could just ignore the message, etch the board and wire the vias through to the top side ground plane. But I would like to know what I’m doing wrong.
Can anybody please help me understand what’s going on?
Thanks