GPS fueled ESP8266 based NTP Server
hardware contains the esp8266 arduino core version used as a git submodule
libraries has all needed libraries as git submodules
eagle contains the schematic and board designs in Eagle cad.
enclosure contains the STL files for the enclosure.
This is designed around this GPS module but any module with standard NMEA output and a pult per second signal will work if you redesign the board or use an adapter.
I also used this display module. You can use others but be careful with the power polarity, I have modules where VCC and ground pins are in a different order.