Also take a look at the better 4-layered version: https://github.com/rallekralle11/Epi_4L
Named after the Epipactis genus or orchids. The flower of one appears on the board.
With such "amazing" features as:
Data line ESD protection taken from the official A. micro.
Crenellated pins.
No integrated voltage converter, only runs at 4,5-5,5v(down to 2,7 if you make it with an 8mhz crystal, or use the internal oscillator).
USB-C connector sunk into the board, and slighly portruding from the end for panel mounting.
1,27mm pin spacing.
Extra pins broken out.
Way too many hours routing for my sanity, and i doubt it's optimal(i am a beginner).
Holes where M2 bolts can be used to hold it in place.
No rx/tx/power LEDs. Only one on pin 13 for testing.
Includes some custom footprints with 3D models.
Size comparisons.
Licensed under CERN-OHL-P v2