Does anybody know how to create a symbol from a simple board file?
Let's say I have a board with a bunch of components on it, plus two connectors. These connectors are board-to-board stackable connectors. I want an easy way to position the connectors on my motherboard.
So, I take a copy of this board file and delete everything on it except the board outline, the padstacks for the stackable connectors, and the pin number text for one of the connectors. Now I want to make a symbol out of this that I can place on my motherboard, without having to calculate the offsets of each connector. I can't figure out how to do that. Can anybody help me?
Creating a mechanical symbol for a board is relatively easy via Skill. I can give you some code for this. However, this will not place the connectors for you - it will just give you a graphical representation of their location. You will still have to place them.
Many companies use a mechanical tool such as Pro-Engineer via an interface to achieve this type of placement.
Sorry, but I have never used a Skill script before - my tier of tool doesn't support Skill very well (OrCAD PCB Designer) anyway.
Anyway, being stubborn, I just tried an experiment - I took my board file, with just the two connectors (pads only, all lines and shapes deleted) and the board outline, and exported the remaining features to a subdrawing (clipboard file). When I imported the clipboard file into a symbol, it seems the padstacks were preserved. Next, I will try to renumber the pads, turn the board outline into a place outline, and try to place the symbol into another board. If that works, I'll report my results.
If anybody else out there has done this, please chime in - I'd like to know if there are any gotcha's.
That actually worked. So, I guess I came up with my own answer. Hopefully this will help others.
There are a couple of tricky parts - if a connector footprint is being changed from SMT to Thruhole, for example, and the origin of the SMT part is in the centre instead of at pin 1, you need to make sure the replacement TH part also has the origin at the centre (do this to the board design before exporting to a subdrawing). Also, all connectors need to be on the same side. If a connector is on the bottom, you need to rotate and mirror (again, do this before exporting).
Finally, because the board is stacked, the symbol needs to be mirrored when placed. So, put the refdes and outline silk on the bottom so that they appear at the top when mirrored (do this to the symbol).