WiFi Time
16 hours ago
- #Abandoned Projects
- #NTP Timing
- #ESP8266
- An ambitious, abandoned project aimed to create a fake GPS module using an ESP8266 to fetch time over WiFi via NTP, targeting sub-millisecond accuracy.
- The goal was to replace GPS breakout boards in a Precision Clock, but indoor GPS issues and WiFi jitter made precision challenging without additional hardware like a TCXO.
- Experiments involved disciplining the ESP8266's internal oscillator using NTP polling, with logic analyzer measurements comparing output to a real GPS PPS signal.
- Key challenges included WiFi packet jitter, systematic offsets from NTP servers, and developing a stable control loop for time synchronization.
- Better results were achieved using specific NTP servers (e.g., time.cloudflare.com) and on networks with less contention, but consistency remained elusive.
- A PCB prototype was designed, but the project was abandoned due to complexity, with the author concluding that a TCXO would have simplified achieving acceptable accuracy.