I am sure that I could produce various Arduino projects as all-in-one boards, but I’m also finding it nice to produce projects that use the standard Arduino Pro Mini boards as pre-built modules. Since I don’t have a pick-and-place machine or a syringe of fresh solder paste, I try to optimize my projects for maximum function with minimum soldering of 0805 smt parts and smaller.
I made a single EAGLE library part that sums up all the features of the Arduino Pro Mini board, so I didn’t have to source and solder the components individually. Note the little PWM indicators.
The only downside is that EAGLE has no good way of identifying two pins that are internally connected. They really need to support that, so that the autorouter will properly bond ground polygons to all ground pads, and give options for reaching the TXO/RXI pins.