I can't find an Eagle library for and 8x8 LED matrix, but I did find a schemtaic that uses one. Is there a way to create a library from the part in the schematic?
Alternatively, can anyone point me to a library for an 8x8 single colour matrix?
If the reference schematic you have was created in EAGLE (*.sch) right click on the part and the info box will indicate which library and other data.
You can copy the part to the same schematic page (using the copy command), or make a group and cut (EAGLE-speak for the the clipboard). Paste the copy on a different sheet in that schematic, or in a different schematic.
Making a new part is more work, and done in the Library Editor. Instead of starting from scratch find a similar symbol, copy and modify it as needed. Next, find a suitable package, copy and modify it as needed, finally create a new device, taking care to hook the symbol pins to the right package pins, and save it. The new part can be added to a schematic.
I haven't used the matrix LEDs (yet...) so I haven't created or borrowed any EAGLE libraries for them, perhaps someone else has done it?