The PCB that was has been already soldered has a bug in the schematic. The AVCC is not connected to VCC.

List of next revision planned fixes and improvements:

1. Fix AVCC bug. (already done)

2. Change all smd R, C components sizes to 0603. (already done)

3. Add GND polygons.

4. Increase the VCC, RAW lines width.

5. Unhide the components designators on PCB.