Chris Liebman is my kind of maker. His projects are interesting, practical and almost always have the words “work in progress” somewhere in the (usually brief) description. I was led to the NTP-server project when following up on his (ESP8266-based) AnalogClock creation (a method of keeping el-cheapo analog clocks in perfect time, even across power outages and daylight-savings time changes, using an ESP8266 and NTP).
The NTP-server is another “work in progress” project, with very little information, other than the code, available. It does hit a couple of sweet spots for me, though:- NTP from a GPS PPS (pulse-per-second) signal and being ESP based (although the breadboard picture shows an ESP32, rather than ESP8266).
Chris is using an Adafruit “Ultimate GPS Breakout” board to provide the PPS signal, as well as serial time and date information to the ESP (the GPS communicates with the ESP via the standard serial pins, while debug-terminal output goes to Serial1).
I have to admit that I haven’t managed to get Chris’ code to compile successfully, yet (you’ll need to download some of Chris’ modified versions of several required libraries to get even close), but this certainly looks like one to keep an eye on (and I’m wondering if a lead soldered to the ‘status’ LED on one of those cheap, USB, GPS dongles would work reliably as a PPS signal source in this case).