PCB board for the GPSDO design developed and documented by AndrewBCN using an STM32F411 Black Pill Arduino Board. The .ino file and upload instructions can be found on my GitHub page: https://github.com/MacMan72/gpsdo as well as links to the GPSDO developers GitHub page documenting the design.
The board size is 83x100mm and works with the following 5V square wave OCXO's or other with the same dimensions and pinouts:
CTI OSC5A2B02
NDK ENE3311
Vectron C4550
etc...
All components needed for the board are called out on the silkscreen. Also required are the STM32F411CEU6 BlackPill Arduino board, a NEO-M8N or similar GPS Module, one of the above listed OCXO's, and the optional Arduino components listed on the PCB (INA219, BMP280, AHT20, TM1637, 128x64 OLED, HC-06 Bluetooth Module). The LVR's are a 5V TO-220 for the OCXO, a 5V TO-92 for the GPS Module, and a 5V TO-252 for the STM32.