Connect all available GND pins on the Pro Micro symbol to your schematic's primary ground net to prevent ground loops and ensure stable signals. PCB Layout Best Practices for the Pro Micro

Ensure you have the 5V/16MHz or 3.3V/8MHz variant selected, though they share the same physical footprint.

Autodesk EAGLE relies on libraries ( .lbr files) to map schematic symbols to physical PCB footprints. Because the Pro Micro is an open-source hardware design originally popularized by SparkFun, several high-quality libraries exist. 1. The SparkFun Eagle Library (Recommended)