Exhibitors 2023

Wi-Fi Enabled Stratum-1 GNSS Time Server Built From Scratch

Wi-Fi Enabled Stratum-1 GNSS Time Server Built From Scratch

My hands-on approach to dissecting IoT from the inside led me to fulfill a long-time dream of having an on-site Stratum-1 Network Time Protocol (NTP) server. NTP is the decades-old synchronization protocol that keeps networked computer clocks accurate.

The best-case scenario for an NTP server is being fed from a Stratum-1 time source, that is, for instance, connected to the source of a VERY accurate time, usually an atomic clock (also called, Stratum-0).

A good amount of Stratum-0 time sources is constantly floating over our heads! The GPS satellites, each one carrying at least two cesium atomic clocks (accurate up to 1 second every 300 million years).

The idea of using GPS as a time source is not new, there are dozens of commercial products available doing precisely that. But my goal is to make it cheap, accurate, self-contained, dual-powered (mains and batteries), wireless-enabled, and portable to use on the field in my HAM Radio activities. Powered by the ever-expanding universe of microcontroller units, this goal is closer than ever.

Current functionalities:

  • Internal RTC synched from GPS satellites constellation (backed by CR2032 battery)

  • Dual voltage powered

  • Backup battery for the whole unit (18650)

  • NTP and RDATE (RFC868) protocols supported

  • WiFi functionality as a client or access point

  • Syslog logging

  • Configuration webpage for WiFi and Syslog, saving to persistent storage (LittleFS)

  • Informative display with a timestamp, satellites in view, accuracy, wifi server, IP address

  • Dual function button, short press switch information on display, long press disables WiFi

  • Status at a glance, with dedicated 5mm LEDs for GPS lock, PPS signal, and WiFi status, as well as visible internal LEDs for charging and GPS module statuses

Wi-Fi Enabled Stratum-1 GNSS Time Server Built From Scratch

Cristiano Reis Monteiro

A science and technology-oriented person, with +25 years of experience with technology as a professional for top 500 companies and as a self-taught coder, maker, and creator.

  C25 (pav. 3C.25)
Data updated on 2024-02-21 - 11.32.43 am