A Global Positioning System (GPS) Disciplined Oscillator (DO)
Please see subdirectory schematics.
The PCB was designed in Autodesk EAGLE 9.6.0 and manufactured by JLCPCB.
The microcontroller is programmed in C using Atmel Studio 7.0.1931 and compiled with avr-gcc as part of the avr8-gnu-toolchain.